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Tapping Into Relief: A Distraction Technique to Reduce Pain During Dermatologic Procedures
Tapping Into Relief: A Distraction Technique to Reduce Pain During Dermatologic Procedures
Practice Gap
Pain during minimally invasive dermatologic procedures such as lidocaine injections, cryotherapy, nail unit injections, and cosmetic procedures including neurotoxin injections can cause patient discomfort leading to procedural anxiety, poor compliance with treatment regimens, and avoidance of necessary care. Current solutions to manage pain during dermatologic procedures present several limitations; for example, topical anesthetics seldom alleviate procedural pain,1 particularly in sensitive areas (eg, nail unit, face) or for patients with a needle phobia. Additionally, topical anesthetics often require up to 2 hours to take effect, making them impractical for quick outpatient procedures. Other pain reduction strategies including vibration devices or cold sprays2,3 can be effective but are an added expense to the physician or clinic, which may preclude their use in resource-limited settings. Psychological distraction techniques such as deep breathing require active patient participation and might reinforce pain expectations and increase patient anxiety.4 Given these challenges, there is a need for effective, affordable, nonpharmacologic pain reduction strategies that can be integrated seamlessly into clinical practice to enhance the patient experience.
The Technique
Tapping is a simple noninvasive distraction technique that may alleviate procedural pain by exploiting the gate control theory of pain.5 According to this theory, tactile stimuli activate mechanoreceptors that send inhibitory signals to the spinal cord, effectively closing the gate to pain transmission. Unlike the Helfer skin tap technique,6 which involves 15 preinjection taps and 3 postinjection taps directly on the injection site, our approach targets distant bony prominences. This modification allows for immediate needle insertion without interfering with the sterile field or increasing the risk for needlestick injuries from tapping near the injection site. Bony sites such as the shoulder or knee are ideal for this technique due to their high density and rigidity that efficiently transmit tactile stimuli––similar to how sound travels faster through solids than through liquids or gases.7
To implement this technique in practice, we first stabilize the injection site to reduce movement from tapping. This can be done by stabilizing the injection site (eg, resting the hand on an instrument stand during a nail unit injection). A second person—such as a medical assistant, medical student, resident, or even the patient’s family member—taps at a distant site at least an arm’s length away from the injection site (Figure). The tapping pressure should be firm enough for the patient to feel the vibration but not forceful enough that it becomes unpleasant or disrupts the injection area. Tapping starts just before needle insertion and continues through the injection. No warning is given to the patient, as the surprise element may help distract them from pain. Varying the rhythm, intensity, or location of the tapping can enhance its distracting effect.

This tapping technique can be effectively combined with other pain reduction strategies in a multimodal approach; for example, when used concurrently with topical anesthetics, both the central (tapping) and peripheral (anesthetic) pain pathways are addressed, potentially yielding additive effects. For patients with a needle phobia, pairing tapping with cognitive distraction (eg, talkesthesia) may further reduce anxiety. In our nail specialty clinic at Weill Cornell Medicine (New York, New York), we often combine tapping with cold sprays and talkesthesia, which improves patient comfort without prolonging the visit. Importantly, the technique enables seamless integration with most pharmacologic and nonpharmacologic methods, eliminating the need for additional patient education or procedure time.
Practice Implications
The tapping technique described here is free, easy to implement, and requires no additional resources aside from another person to tap the patient during the procedure. It can be used for a wide range of dermatologic procedures, including biopsies, intralesional injections, and cosmetic treatments, including neurotoxin injections. The minimal learning curve and ease of integration into procedural workflows make this technique a valuable tool for dermatologists aiming to improve patient comfort without disrupting workflow. In our practice, we have observed that tapping reduces self-reported pain and helps ease anxiety, particularly in patients with a needle phobia. Its simplicity and accessibility make it a valuable addition to a wide range of dermatologic procedures. Prospective studies investigating patient-reported outcomes could help establish this technique’s role in clinical practice.
- Navarro-Rodriguez JM, Suarez-Serrano C, Martin-Valero R, et al. Effectiveness of topical anesthetics in pain management for dermal injuries: a systematic review. J Clin Med. 2021;10:2522. doi:10.3390/jcm10112522
- Lipner SR. Pain-minimizing strategies for nail surgery. Cutis. 2018;101:76-77.
- Ricardo JW, Lipner SR. Air cooling for improved analgesia during local anesthetic infiltration for nail surgery. J Am Acad Dermatol. 2021;84:e231-e232. doi:10.1016/j.jaad.2019.11.032
- Hill RC, Chernoff KA, Lipner SR. A breath of fresh air: use of deep breathing technique to minimize pain with nail injections. J Am Acad Dermatol. 2024;90:e163. doi:10.1016/j.jaad.2023.10.043
- Mendell LM. Constructing and deconstructing the gate theory of pain. Pain. 2014;155:210-216. doi:10.1016/j.pain.2013.12.010
- Jyoti G, Arora S, Sharma B. Helfer Skin Tap Tech Technique for the IM injection pain among adult patients. Nursing & Midwifery Research Journal. 2018;14:18-30. doi:10.1177/0974150X20180304
- Iowa State University. Nondestructive Evaluation Physics: Sound. Published 2021. Accessed July 31, 2025. https://www.nde-ed.org/Physics/Sound/speedinmaterials.xhtml
Practice Gap
Pain during minimally invasive dermatologic procedures such as lidocaine injections, cryotherapy, nail unit injections, and cosmetic procedures including neurotoxin injections can cause patient discomfort leading to procedural anxiety, poor compliance with treatment regimens, and avoidance of necessary care. Current solutions to manage pain during dermatologic procedures present several limitations; for example, topical anesthetics seldom alleviate procedural pain,1 particularly in sensitive areas (eg, nail unit, face) or for patients with a needle phobia. Additionally, topical anesthetics often require up to 2 hours to take effect, making them impractical for quick outpatient procedures. Other pain reduction strategies including vibration devices or cold sprays2,3 can be effective but are an added expense to the physician or clinic, which may preclude their use in resource-limited settings. Psychological distraction techniques such as deep breathing require active patient participation and might reinforce pain expectations and increase patient anxiety.4 Given these challenges, there is a need for effective, affordable, nonpharmacologic pain reduction strategies that can be integrated seamlessly into clinical practice to enhance the patient experience.
The Technique
Tapping is a simple noninvasive distraction technique that may alleviate procedural pain by exploiting the gate control theory of pain.5 According to this theory, tactile stimuli activate mechanoreceptors that send inhibitory signals to the spinal cord, effectively closing the gate to pain transmission. Unlike the Helfer skin tap technique,6 which involves 15 preinjection taps and 3 postinjection taps directly on the injection site, our approach targets distant bony prominences. This modification allows for immediate needle insertion without interfering with the sterile field or increasing the risk for needlestick injuries from tapping near the injection site. Bony sites such as the shoulder or knee are ideal for this technique due to their high density and rigidity that efficiently transmit tactile stimuli––similar to how sound travels faster through solids than through liquids or gases.7
To implement this technique in practice, we first stabilize the injection site to reduce movement from tapping. This can be done by stabilizing the injection site (eg, resting the hand on an instrument stand during a nail unit injection). A second person—such as a medical assistant, medical student, resident, or even the patient’s family member—taps at a distant site at least an arm’s length away from the injection site (Figure). The tapping pressure should be firm enough for the patient to feel the vibration but not forceful enough that it becomes unpleasant or disrupts the injection area. Tapping starts just before needle insertion and continues through the injection. No warning is given to the patient, as the surprise element may help distract them from pain. Varying the rhythm, intensity, or location of the tapping can enhance its distracting effect.

This tapping technique can be effectively combined with other pain reduction strategies in a multimodal approach; for example, when used concurrently with topical anesthetics, both the central (tapping) and peripheral (anesthetic) pain pathways are addressed, potentially yielding additive effects. For patients with a needle phobia, pairing tapping with cognitive distraction (eg, talkesthesia) may further reduce anxiety. In our nail specialty clinic at Weill Cornell Medicine (New York, New York), we often combine tapping with cold sprays and talkesthesia, which improves patient comfort without prolonging the visit. Importantly, the technique enables seamless integration with most pharmacologic and nonpharmacologic methods, eliminating the need for additional patient education or procedure time.
Practice Implications
The tapping technique described here is free, easy to implement, and requires no additional resources aside from another person to tap the patient during the procedure. It can be used for a wide range of dermatologic procedures, including biopsies, intralesional injections, and cosmetic treatments, including neurotoxin injections. The minimal learning curve and ease of integration into procedural workflows make this technique a valuable tool for dermatologists aiming to improve patient comfort without disrupting workflow. In our practice, we have observed that tapping reduces self-reported pain and helps ease anxiety, particularly in patients with a needle phobia. Its simplicity and accessibility make it a valuable addition to a wide range of dermatologic procedures. Prospective studies investigating patient-reported outcomes could help establish this technique’s role in clinical practice.
Practice Gap
Pain during minimally invasive dermatologic procedures such as lidocaine injections, cryotherapy, nail unit injections, and cosmetic procedures including neurotoxin injections can cause patient discomfort leading to procedural anxiety, poor compliance with treatment regimens, and avoidance of necessary care. Current solutions to manage pain during dermatologic procedures present several limitations; for example, topical anesthetics seldom alleviate procedural pain,1 particularly in sensitive areas (eg, nail unit, face) or for patients with a needle phobia. Additionally, topical anesthetics often require up to 2 hours to take effect, making them impractical for quick outpatient procedures. Other pain reduction strategies including vibration devices or cold sprays2,3 can be effective but are an added expense to the physician or clinic, which may preclude their use in resource-limited settings. Psychological distraction techniques such as deep breathing require active patient participation and might reinforce pain expectations and increase patient anxiety.4 Given these challenges, there is a need for effective, affordable, nonpharmacologic pain reduction strategies that can be integrated seamlessly into clinical practice to enhance the patient experience.
The Technique
Tapping is a simple noninvasive distraction technique that may alleviate procedural pain by exploiting the gate control theory of pain.5 According to this theory, tactile stimuli activate mechanoreceptors that send inhibitory signals to the spinal cord, effectively closing the gate to pain transmission. Unlike the Helfer skin tap technique,6 which involves 15 preinjection taps and 3 postinjection taps directly on the injection site, our approach targets distant bony prominences. This modification allows for immediate needle insertion without interfering with the sterile field or increasing the risk for needlestick injuries from tapping near the injection site. Bony sites such as the shoulder or knee are ideal for this technique due to their high density and rigidity that efficiently transmit tactile stimuli––similar to how sound travels faster through solids than through liquids or gases.7
To implement this technique in practice, we first stabilize the injection site to reduce movement from tapping. This can be done by stabilizing the injection site (eg, resting the hand on an instrument stand during a nail unit injection). A second person—such as a medical assistant, medical student, resident, or even the patient’s family member—taps at a distant site at least an arm’s length away from the injection site (Figure). The tapping pressure should be firm enough for the patient to feel the vibration but not forceful enough that it becomes unpleasant or disrupts the injection area. Tapping starts just before needle insertion and continues through the injection. No warning is given to the patient, as the surprise element may help distract them from pain. Varying the rhythm, intensity, or location of the tapping can enhance its distracting effect.

This tapping technique can be effectively combined with other pain reduction strategies in a multimodal approach; for example, when used concurrently with topical anesthetics, both the central (tapping) and peripheral (anesthetic) pain pathways are addressed, potentially yielding additive effects. For patients with a needle phobia, pairing tapping with cognitive distraction (eg, talkesthesia) may further reduce anxiety. In our nail specialty clinic at Weill Cornell Medicine (New York, New York), we often combine tapping with cold sprays and talkesthesia, which improves patient comfort without prolonging the visit. Importantly, the technique enables seamless integration with most pharmacologic and nonpharmacologic methods, eliminating the need for additional patient education or procedure time.
Practice Implications
The tapping technique described here is free, easy to implement, and requires no additional resources aside from another person to tap the patient during the procedure. It can be used for a wide range of dermatologic procedures, including biopsies, intralesional injections, and cosmetic treatments, including neurotoxin injections. The minimal learning curve and ease of integration into procedural workflows make this technique a valuable tool for dermatologists aiming to improve patient comfort without disrupting workflow. In our practice, we have observed that tapping reduces self-reported pain and helps ease anxiety, particularly in patients with a needle phobia. Its simplicity and accessibility make it a valuable addition to a wide range of dermatologic procedures. Prospective studies investigating patient-reported outcomes could help establish this technique’s role in clinical practice.
- Navarro-Rodriguez JM, Suarez-Serrano C, Martin-Valero R, et al. Effectiveness of topical anesthetics in pain management for dermal injuries: a systematic review. J Clin Med. 2021;10:2522. doi:10.3390/jcm10112522
- Lipner SR. Pain-minimizing strategies for nail surgery. Cutis. 2018;101:76-77.
- Ricardo JW, Lipner SR. Air cooling for improved analgesia during local anesthetic infiltration for nail surgery. J Am Acad Dermatol. 2021;84:e231-e232. doi:10.1016/j.jaad.2019.11.032
- Hill RC, Chernoff KA, Lipner SR. A breath of fresh air: use of deep breathing technique to minimize pain with nail injections. J Am Acad Dermatol. 2024;90:e163. doi:10.1016/j.jaad.2023.10.043
- Mendell LM. Constructing and deconstructing the gate theory of pain. Pain. 2014;155:210-216. doi:10.1016/j.pain.2013.12.010
- Jyoti G, Arora S, Sharma B. Helfer Skin Tap Tech Technique for the IM injection pain among adult patients. Nursing & Midwifery Research Journal. 2018;14:18-30. doi:10.1177/0974150X20180304
- Iowa State University. Nondestructive Evaluation Physics: Sound. Published 2021. Accessed July 31, 2025. https://www.nde-ed.org/Physics/Sound/speedinmaterials.xhtml
- Navarro-Rodriguez JM, Suarez-Serrano C, Martin-Valero R, et al. Effectiveness of topical anesthetics in pain management for dermal injuries: a systematic review. J Clin Med. 2021;10:2522. doi:10.3390/jcm10112522
- Lipner SR. Pain-minimizing strategies for nail surgery. Cutis. 2018;101:76-77.
- Ricardo JW, Lipner SR. Air cooling for improved analgesia during local anesthetic infiltration for nail surgery. J Am Acad Dermatol. 2021;84:e231-e232. doi:10.1016/j.jaad.2019.11.032
- Hill RC, Chernoff KA, Lipner SR. A breath of fresh air: use of deep breathing technique to minimize pain with nail injections. J Am Acad Dermatol. 2024;90:e163. doi:10.1016/j.jaad.2023.10.043
- Mendell LM. Constructing and deconstructing the gate theory of pain. Pain. 2014;155:210-216. doi:10.1016/j.pain.2013.12.010
- Jyoti G, Arora S, Sharma B. Helfer Skin Tap Tech Technique for the IM injection pain among adult patients. Nursing & Midwifery Research Journal. 2018;14:18-30. doi:10.1177/0974150X20180304
- Iowa State University. Nondestructive Evaluation Physics: Sound. Published 2021. Accessed July 31, 2025. https://www.nde-ed.org/Physics/Sound/speedinmaterials.xhtml
Tapping Into Relief: A Distraction Technique to Reduce Pain During Dermatologic Procedures
Tapping Into Relief: A Distraction Technique to Reduce Pain During Dermatologic Procedures
A Cross-Sectional Analysis of TikTok Skin Care Routines and the Associated Environmental Impact
A Cross-Sectional Analysis of TikTok Skin Care Routines and the Associated Environmental Impact
To the Editor:
The popularity of the social media platform TikTok, which is known for its short-form videos, has surged in recent years. Viral videos demonstrating skin care routines reach millions of viewers,1 showcasing specific products, detailing beauty regimens, and setting fads that many users eagerly follow. These trends often influence consumer behavior—in 2023, viral videos using the tag #TikTokMadeMeBuy lead to a 14% growth in the sale of skin care products.2 However, they also encourage purchasing decisions that may escalate environmental waste through plastic packaging and single-use products. In this study, we analyzed videos on TikTok to assess the environmental impact of trending skin care routines. By examining the types of products promoted, their packaging, and the frequency with which they appear in viral content, we aimed to investigate how these trends, which may be imitated by users, impact the environment.
A search of TikTok videos using #skincareroutine was conducted on June 21, 2024. Sponsored content, non–English language videos, videos without demonstrated skin care routines, and videos showing makeup routines were excluded from our analysis. Data collected from each video included username, date posted, number of likes, total number of skin care products used, number of single-use skin care products used, average amount of product used, number of skin care applicators used, and number of single-use applicators used. Single-use items, defined as those intended for one-time use and subsequent disposal, were identified visually by packaging, manufacturer intent, and common consumer usage patterns. The amount of product used per application was graded on a scale of 1 to 3 (1=pea-sized amount or less; 2=single full pump/spray; 3=multiple pumps/sprays). Videos were categorized as personal (ie, skin care routine walk-throughs by the creator) or autonomous sensory meridian response (ASMR)(focused on product sounds and aesthetics).3 A Mann-Whitney U test was utilized to statistically compare the 2 groups. Statistical analysis was performed using Microsoft Excel (α=0.05).
A total of 50 videos met the inclusion criteria and were included in the analysis. The average number of likes per video was 499,696.15, with skin care routines featuring an average of 6.4 unique products (Table). There was a weak positive correlation (r=0.1809) between the number of skin care products used and the number of likes. A total of 320 products were used across the videos, 23 of which were single-use (7.2%).On average, single-use skin care items were used 0.46 times per routine, comprising a mean 7.99% of total products per video. The average score for the amount of product used per application was 2.18. There was no difference in personal vs ASMR videos with regard to the total number of skin care products used or the average amount of product used per application (P>.05). Thirty-three (70.2%) of the 47 applicators used across all videos were single-use. An average of 0.94 applicators per routine were utilized, with a mean 68.83% being single-use applicators. Common single-use products were toner wipes and eye patches, and single-use applicators included cotton pads and plastic spatulas.
Our findings indicated a prevalence of multiple products and large amount of product used in trending skin care routines, suggesting a shift toward multistep skin care. This implies a high rate of product consumption that may accelerate the carbon footprint associated with skin care products,3 which could contribute to climate change and environmental degradation. Consumers also may feel compelled to purchase and discard numerous partially used products in order to keep up with the latest trends, exacerbating the environmental impact. Furthermore, the utilization of single-use products and applicators contributes to increased plastic waste, pollution, and resource depletion. Single-use items often are difficult to recycle due to their mixed materials and small size,4,5 and therefore they can accumulate in landfills and oceans. This impact can be mitigated by switching to reusable applicators, refillable packaging, and biodegradable materials.
The substantial average number of likes per video indicates high engagement with skin care content among TikTok users. The continued popularity of complex multistep skin care routines, despite a weak correlation between the number of skin care products used and the number of likes per video, likely stems from factors such as aesthetic appeal, ASMR effects, and creators’ established followings, which may drive user engagement to contribute to unsustainable consumption patterns. Factors such as presentation style, aesthetics, or creators’ pre-existing online following may have a major impact on how well a video performs on TikTok. The similarity between personal and ASMR videos, particularly in the number of products used and the amount applied, suggests that both formats employ common approaches to meet audience expectations and align with promotional trends, relying more on sensory and aesthetic strategies than substantive differences in skin care routines.
Our use of only one tag in our search as well as the subjective quantity scale limits the generalizability of these findings to broader TikTok skin care content.
Overall, our study underscores the role of brands and social media influencers in skin care education and promotion of sustainable practices. The extensive number of products used and generous application of each product in skin care routines demonstrated in TikTok videos may mislead viewers into believing that using more product improves outcomes, when often, less is more. We recommend that dermatologists counsel patients about informed skin care regimens that prioritize individual needs over social media fads.
- Pagani K, Lukac D, Martinez R, et al. Slugging: TikTokTM as a source of a viral “harmless” beauty trend. Clin Dermatol. 2022;40:810-812. doi:10.1016/j.clindermatol.2022.08.005
- Stern C. TikTok drives $31.7B in beauty sales: how viral trends are shaping the future of cosmetics. CosmeticsDesign. August 20, 2024. Accessed June 24, 2025. https://www.cosmeticsdesign.com/Article/2024/08/20/tiktok-drives-31.7b-in-beauty-sales-how-viral-trends-are-shaping-the-future-of-cosmetics/
- Fountain C. ASMR content saw huge growth on YouTube, but now creators are flocking to TikTok instead. Business Insider. July 4, 2022. Accessed June 24, 2025. https://www.businessinsider.com/asmr-tiktok-instead-of-youtube-growth-subscribers-2022-7
- Rathore S, Schuler B, Park J. Life cycle assessment of multiple dispensing systems used for cosmetic product packaging. Packaging Technol Sci. 2023;36:533-547. doi:10.1002/pts.2729
- Shaw S. How to actually recycle your empty beauty products. CNN Underscored. Updated April 17, 2024. Accessed June 24, 2025. https://www.cnn.com/cnn-underscored/beauty/how-to-recycle-beauty-products
To the Editor:
The popularity of the social media platform TikTok, which is known for its short-form videos, has surged in recent years. Viral videos demonstrating skin care routines reach millions of viewers,1 showcasing specific products, detailing beauty regimens, and setting fads that many users eagerly follow. These trends often influence consumer behavior—in 2023, viral videos using the tag #TikTokMadeMeBuy lead to a 14% growth in the sale of skin care products.2 However, they also encourage purchasing decisions that may escalate environmental waste through plastic packaging and single-use products. In this study, we analyzed videos on TikTok to assess the environmental impact of trending skin care routines. By examining the types of products promoted, their packaging, and the frequency with which they appear in viral content, we aimed to investigate how these trends, which may be imitated by users, impact the environment.
A search of TikTok videos using #skincareroutine was conducted on June 21, 2024. Sponsored content, non–English language videos, videos without demonstrated skin care routines, and videos showing makeup routines were excluded from our analysis. Data collected from each video included username, date posted, number of likes, total number of skin care products used, number of single-use skin care products used, average amount of product used, number of skin care applicators used, and number of single-use applicators used. Single-use items, defined as those intended for one-time use and subsequent disposal, were identified visually by packaging, manufacturer intent, and common consumer usage patterns. The amount of product used per application was graded on a scale of 1 to 3 (1=pea-sized amount or less; 2=single full pump/spray; 3=multiple pumps/sprays). Videos were categorized as personal (ie, skin care routine walk-throughs by the creator) or autonomous sensory meridian response (ASMR)(focused on product sounds and aesthetics).3 A Mann-Whitney U test was utilized to statistically compare the 2 groups. Statistical analysis was performed using Microsoft Excel (α=0.05).
A total of 50 videos met the inclusion criteria and were included in the analysis. The average number of likes per video was 499,696.15, with skin care routines featuring an average of 6.4 unique products (Table). There was a weak positive correlation (r=0.1809) between the number of skin care products used and the number of likes. A total of 320 products were used across the videos, 23 of which were single-use (7.2%).On average, single-use skin care items were used 0.46 times per routine, comprising a mean 7.99% of total products per video. The average score for the amount of product used per application was 2.18. There was no difference in personal vs ASMR videos with regard to the total number of skin care products used or the average amount of product used per application (P>.05). Thirty-three (70.2%) of the 47 applicators used across all videos were single-use. An average of 0.94 applicators per routine were utilized, with a mean 68.83% being single-use applicators. Common single-use products were toner wipes and eye patches, and single-use applicators included cotton pads and plastic spatulas.
Our findings indicated a prevalence of multiple products and large amount of product used in trending skin care routines, suggesting a shift toward multistep skin care. This implies a high rate of product consumption that may accelerate the carbon footprint associated with skin care products,3 which could contribute to climate change and environmental degradation. Consumers also may feel compelled to purchase and discard numerous partially used products in order to keep up with the latest trends, exacerbating the environmental impact. Furthermore, the utilization of single-use products and applicators contributes to increased plastic waste, pollution, and resource depletion. Single-use items often are difficult to recycle due to their mixed materials and small size,4,5 and therefore they can accumulate in landfills and oceans. This impact can be mitigated by switching to reusable applicators, refillable packaging, and biodegradable materials.
The substantial average number of likes per video indicates high engagement with skin care content among TikTok users. The continued popularity of complex multistep skin care routines, despite a weak correlation between the number of skin care products used and the number of likes per video, likely stems from factors such as aesthetic appeal, ASMR effects, and creators’ established followings, which may drive user engagement to contribute to unsustainable consumption patterns. Factors such as presentation style, aesthetics, or creators’ pre-existing online following may have a major impact on how well a video performs on TikTok. The similarity between personal and ASMR videos, particularly in the number of products used and the amount applied, suggests that both formats employ common approaches to meet audience expectations and align with promotional trends, relying more on sensory and aesthetic strategies than substantive differences in skin care routines.
Our use of only one tag in our search as well as the subjective quantity scale limits the generalizability of these findings to broader TikTok skin care content.
Overall, our study underscores the role of brands and social media influencers in skin care education and promotion of sustainable practices. The extensive number of products used and generous application of each product in skin care routines demonstrated in TikTok videos may mislead viewers into believing that using more product improves outcomes, when often, less is more. We recommend that dermatologists counsel patients about informed skin care regimens that prioritize individual needs over social media fads.
To the Editor:
The popularity of the social media platform TikTok, which is known for its short-form videos, has surged in recent years. Viral videos demonstrating skin care routines reach millions of viewers,1 showcasing specific products, detailing beauty regimens, and setting fads that many users eagerly follow. These trends often influence consumer behavior—in 2023, viral videos using the tag #TikTokMadeMeBuy lead to a 14% growth in the sale of skin care products.2 However, they also encourage purchasing decisions that may escalate environmental waste through plastic packaging and single-use products. In this study, we analyzed videos on TikTok to assess the environmental impact of trending skin care routines. By examining the types of products promoted, their packaging, and the frequency with which they appear in viral content, we aimed to investigate how these trends, which may be imitated by users, impact the environment.
A search of TikTok videos using #skincareroutine was conducted on June 21, 2024. Sponsored content, non–English language videos, videos without demonstrated skin care routines, and videos showing makeup routines were excluded from our analysis. Data collected from each video included username, date posted, number of likes, total number of skin care products used, number of single-use skin care products used, average amount of product used, number of skin care applicators used, and number of single-use applicators used. Single-use items, defined as those intended for one-time use and subsequent disposal, were identified visually by packaging, manufacturer intent, and common consumer usage patterns. The amount of product used per application was graded on a scale of 1 to 3 (1=pea-sized amount or less; 2=single full pump/spray; 3=multiple pumps/sprays). Videos were categorized as personal (ie, skin care routine walk-throughs by the creator) or autonomous sensory meridian response (ASMR)(focused on product sounds and aesthetics).3 A Mann-Whitney U test was utilized to statistically compare the 2 groups. Statistical analysis was performed using Microsoft Excel (α=0.05).
A total of 50 videos met the inclusion criteria and were included in the analysis. The average number of likes per video was 499,696.15, with skin care routines featuring an average of 6.4 unique products (Table). There was a weak positive correlation (r=0.1809) between the number of skin care products used and the number of likes. A total of 320 products were used across the videos, 23 of which were single-use (7.2%).On average, single-use skin care items were used 0.46 times per routine, comprising a mean 7.99% of total products per video. The average score for the amount of product used per application was 2.18. There was no difference in personal vs ASMR videos with regard to the total number of skin care products used or the average amount of product used per application (P>.05). Thirty-three (70.2%) of the 47 applicators used across all videos were single-use. An average of 0.94 applicators per routine were utilized, with a mean 68.83% being single-use applicators. Common single-use products were toner wipes and eye patches, and single-use applicators included cotton pads and plastic spatulas.
Our findings indicated a prevalence of multiple products and large amount of product used in trending skin care routines, suggesting a shift toward multistep skin care. This implies a high rate of product consumption that may accelerate the carbon footprint associated with skin care products,3 which could contribute to climate change and environmental degradation. Consumers also may feel compelled to purchase and discard numerous partially used products in order to keep up with the latest trends, exacerbating the environmental impact. Furthermore, the utilization of single-use products and applicators contributes to increased plastic waste, pollution, and resource depletion. Single-use items often are difficult to recycle due to their mixed materials and small size,4,5 and therefore they can accumulate in landfills and oceans. This impact can be mitigated by switching to reusable applicators, refillable packaging, and biodegradable materials.
The substantial average number of likes per video indicates high engagement with skin care content among TikTok users. The continued popularity of complex multistep skin care routines, despite a weak correlation between the number of skin care products used and the number of likes per video, likely stems from factors such as aesthetic appeal, ASMR effects, and creators’ established followings, which may drive user engagement to contribute to unsustainable consumption patterns. Factors such as presentation style, aesthetics, or creators’ pre-existing online following may have a major impact on how well a video performs on TikTok. The similarity between personal and ASMR videos, particularly in the number of products used and the amount applied, suggests that both formats employ common approaches to meet audience expectations and align with promotional trends, relying more on sensory and aesthetic strategies than substantive differences in skin care routines.
Our use of only one tag in our search as well as the subjective quantity scale limits the generalizability of these findings to broader TikTok skin care content.
Overall, our study underscores the role of brands and social media influencers in skin care education and promotion of sustainable practices. The extensive number of products used and generous application of each product in skin care routines demonstrated in TikTok videos may mislead viewers into believing that using more product improves outcomes, when often, less is more. We recommend that dermatologists counsel patients about informed skin care regimens that prioritize individual needs over social media fads.
- Pagani K, Lukac D, Martinez R, et al. Slugging: TikTokTM as a source of a viral “harmless” beauty trend. Clin Dermatol. 2022;40:810-812. doi:10.1016/j.clindermatol.2022.08.005
- Stern C. TikTok drives $31.7B in beauty sales: how viral trends are shaping the future of cosmetics. CosmeticsDesign. August 20, 2024. Accessed June 24, 2025. https://www.cosmeticsdesign.com/Article/2024/08/20/tiktok-drives-31.7b-in-beauty-sales-how-viral-trends-are-shaping-the-future-of-cosmetics/
- Fountain C. ASMR content saw huge growth on YouTube, but now creators are flocking to TikTok instead. Business Insider. July 4, 2022. Accessed June 24, 2025. https://www.businessinsider.com/asmr-tiktok-instead-of-youtube-growth-subscribers-2022-7
- Rathore S, Schuler B, Park J. Life cycle assessment of multiple dispensing systems used for cosmetic product packaging. Packaging Technol Sci. 2023;36:533-547. doi:10.1002/pts.2729
- Shaw S. How to actually recycle your empty beauty products. CNN Underscored. Updated April 17, 2024. Accessed June 24, 2025. https://www.cnn.com/cnn-underscored/beauty/how-to-recycle-beauty-products
- Pagani K, Lukac D, Martinez R, et al. Slugging: TikTokTM as a source of a viral “harmless” beauty trend. Clin Dermatol. 2022;40:810-812. doi:10.1016/j.clindermatol.2022.08.005
- Stern C. TikTok drives $31.7B in beauty sales: how viral trends are shaping the future of cosmetics. CosmeticsDesign. August 20, 2024. Accessed June 24, 2025. https://www.cosmeticsdesign.com/Article/2024/08/20/tiktok-drives-31.7b-in-beauty-sales-how-viral-trends-are-shaping-the-future-of-cosmetics/
- Fountain C. ASMR content saw huge growth on YouTube, but now creators are flocking to TikTok instead. Business Insider. July 4, 2022. Accessed June 24, 2025. https://www.businessinsider.com/asmr-tiktok-instead-of-youtube-growth-subscribers-2022-7
- Rathore S, Schuler B, Park J. Life cycle assessment of multiple dispensing systems used for cosmetic product packaging. Packaging Technol Sci. 2023;36:533-547. doi:10.1002/pts.2729
- Shaw S. How to actually recycle your empty beauty products. CNN Underscored. Updated April 17, 2024. Accessed June 24, 2025. https://www.cnn.com/cnn-underscored/beauty/how-to-recycle-beauty-products
A Cross-Sectional Analysis of TikTok Skin Care Routines and the Associated Environmental Impact
A Cross-Sectional Analysis of TikTok Skin Care Routines and the Associated Environmental Impact
PRACTICE POINTS
- Social media platforms are increasingly influential in shaping consumer skin care habits, particularly among younger demographics.
- Dermatologists should be aware of the aestheticdriven nature of online skin care trends when advising patients on product use.
- Viral skin care routines often feature multiple products and applicators, potentially encouraging excessive product use and waste.
Approach to Diagnosing and Managing Implantation Mycoses
Approach to Diagnosing and Managing Implantation Mycoses
Implantation mycoses such as chromoblastomycosis, subcutaneous phaeohyphomycosis, and mycetoma are a diverse group of fungal diseases that occur when a break in the skin allows the entry of the causative fungus. These diseases disproportionately affect individuals in low- and middle-income countries causing substantial disability, decreased quality of life, and severe social stigma.1-3 Timely diagnosis and appropriate treatment are critical.
Chromoblastomycosis and mycetoma are designated as neglected tropical diseases, but research to improve their management is sparse, even compared to other neglected tropical diseases.4,5 Since there are no global diagnostic and treatment guidelines to date, we outline steps to diagnose and manage chromoblastomycosis, subcutaneous phaeohyphomycosis, and mycetoma.
Chromoblastomycosis
Chromoblastomycosis is caused by dematiaceous fungi that typically affect the skin and subcutaneous tissue. Chromoblastomycosis is distinguished from subcutaneous phaeohyphomycosis by microscopically visualizing the characteristic thick-walled, single, or multicellular clusters of pigmented fungal cells (also known as medlar bodies, muriform cells, or sclerotic bodies).6 In phaeohyphomycosis, short hyphae and pseudohyphae plus some single cells typically are seen.
Epidemiology—Globally, the distribution and burden of chromoblastomycosis are relatively unknown. Infections are more common in tropical and subtropical areas but can be acquired anywhere. A literature review conducted in 2021 identified 7740 cases of chromoblastomycosis, mostly reported in South America, Africa, Central America and Mexico, and Asia.7 Most of the patients were male, and the median age was 52 years. One study found an incidence of 14.7 per 1,000,000 patients in the United States for both chromoblastomycosis and phaeohyphomycotic abscesses (which included both skin and brain abscesses).8 Most patients were aged 65 years or older, with a higher incidence in males. Geographically, the incidence was highest in the Northeast followed by the South; patients in rural areas also had higher incidence of disease.8
Causative Organisms—Causative species cannot reliably distinguish between chromoblastomycosis and subcutaneous phaeohyphomycosis, as some species overlap. Cladophialophora carrionii, Fonsecaea species, Phialophora verrucosa species complex, and Rhinocladiella aquaspersa most commonly cause chromoblastomycosis.9,10
Clinical Manifestations—Chromoblastomycosis initially manifests as a solitary erythematous macule at a site of trauma (often not recalled by the patient) that can evolve to a smooth pink papule and may progress to 1 of 5 morphologies: nodular, verrucous, tumorous, cicatricial, or plaque.6 Patients may present with more than one morphology, particularly in long-standing or advanced disease. Lesions commonly manifest on the arms and legs in otherwise healthy individuals in environments (eg, rural, agricultural) that have more opportunities for injury and exposure to the causative fungi. Affected individuals often have small black specks on the lesion surface that are visible with the naked eye.6
Diagnosis—Common differential diagnoses include cutaneous blastomycosis, fixed sporotrichosis, warty tuberculosis nocardiosis, cutaneous leishmaniasis, human papillomavirus (HPV) infection, podoconiosis, lymphatic filariasis, cutaneous tuberculosis, and psoriasis.6 Squamous cell carcinoma is both a differential diagnosis as well as a potential complication of the disease.11
Potassium hydroxide preparation with skin scapings or a biopsy from the lesion has high sensitivity and quick turnaround times. There often is a background histopathologic reaction of pseudoepitheliomatous hyperplasia. Examining samples taken from areas with the visible small black dots on the skin surface can increase the likelihood of detecting fungal elements (Figure 1). Clinicians also may choose to obtain a 6- to 8-mm deep skin biopsy from the lesion and splice it in half, with one sample sent for histopathology and the other for culture (Figure 2). Skin scrapings can be sent for culture instead. In the case of verrucous lesions, biopsy is preferred if feasible.


Treatment should not be delayed while awaiting the culture results if infection is otherwise confirmed by direct microscopy or histopathology. The treatment approach remains similar regardless of the causative species. If the culture results are positive, the causative genus can be identified by the microscopic morphology; however, molecular diagnostic tools are needed for accurate species identification.12,13
Antifungal Susceptibility Testing—For most dematiaceous fungi, interpreting minimum inhibitory concentrations (MICs) is challenging due to a lack of data from multicenter studies. One report examined sequential isolates of Fonsecaea pedrosoi and demonstrated both high MIC values and clinical resistance to itraconazole in some cases, likely from treatment pressure.14 Clinical Laboratory Standards Institute–approved epidemiologic cutoff values (ECVs) are established for F pedrosoi for commonly used antifungals including itraconazole (0.5 µg/mL), terbinafine (0.25 µg/mL), and posaconazole (0.5 µg/mL).15 Clinicians may choose to obtain sequential isolates for any causative fungi in recalcitrant disease to monitor for increases in MIC.
Management—In early-stage disease, excision of the skin nodule may be curative, although concomitant treatment for several months with an antifungal is advised. If antifungals are needed, itraconazole is the most commonly prescribed agent, typically at a dose of 100 to 200 mg twice daily. Terbinafine also has been used first-line at a dose of 250 to 500 mg per day. Voriconazole and posaconazole also may be suitable options for first-line or for refractory disease treatment. Fluconazole does not have good activity against dematiaceous fungi and should be avoided.16 Topical antifungals will not reach the site of infection in adequate concentrations. Topical corticosteroids can make the disease worse and should be avoided. The duration of therapy usually is several months, but many patients require years of therapy until resolution of lesions.
Clinicians can consider combination therapy with an antifungal and a topical immunomodulator such as imiquimod (applied topically 3 times per week); this combination can be considered in refractory disease and even upon initial diagnosis, especially in severe disease.17,18 Nonpharmacologic interventions such as cryotherapy, heat, and light-based therapies have been used, but outcome data are scarce.19-23
Subcutaneous Phaeohyphomycosis
Subcutaneous phaeohyphomycosis also is caused by dematiaceous fungi that typically affect the skin and subcutaneous tissue. Subcutaneous phaeohyphomycosis is distinguished from chromoblastomycosis by short hyphae and hyphal fragments usually seen microscopically instead of visualizing thick-walled, single, or multicellular clusters of pigmented fungal cells.6
Epidemiology—Globally, the burden and distribution of phaeohyphomycosis, including its cutaneous manifestations, are not well understood. Infections are more common in tropical and subtropical areas but can be acquired anywhere. Phaeohyphomycosis is a generic term used to describe infections caused by pigmented hyphal fungi that can manifest on the skin (subcutaneous phaeohyphomycosis) but also can affect deep structures including the brain (systemic phaeohyphomycosis).24
Causative Organisms—Alternaria, Bipolaris, Cladosporium, Curvularia, Exophiala, and Exserohilum species most commonly cause subcutaneous phaeohyphomycosis. Alternaria infections manifesting with skin lesions often are referred to as cutaneous alternariosis.25
Clinical Manifestations—The most common skin manifestation of phaeohyphomycosis is a subcutaneous cyst (cystic phaeohyphomycosis)(Figure 2). Subcutaneous phaeohyphomycosis also may manifest with nodules or plaques (Figure 3). Phaeohyphomycosis appears to occur more commonly in individuals who are immunosuppressed, those in whom T-cell function is affected, in congenital immunodeficiency states (eg, individuals with CARD9 mutations).26

Diagnosis—Culture is the gold standard for confirming phaeohyphomycosis.27 For cystic phaeohyphomycosis, clinicians can consider aspiration of the cyst for direct microscopic examination and culture. Histopathology may be utilized but can have lower sensitivity in showing dematiaceous hyphae and granulomatous inflammation; using the Masson-Fontana stain for melanin can be helpful. Molecular diagnostic tools including metagenomics applied directly to the tissue may be useful but are likely to have lower sensitivity than culture and require specialist diagnostic facilities.
Management—The approaches to managing chromoblastomycosis and subcutaneous phaeohyphomycosis are similar, though the preferred agents often differ. In early-stage disease, excision of the skin nodule may be curative, although concomitant treatment for several months with an antifungal is advised. In localized forms, itraconazole usually is used, but in those cases associated with immunodeficiency states, voriconazole may be necessary. Fluconazole does not have good activity against dematiaceous fungi and should be avoided.16 Topical antifungals will not reach the site of infection in adequate concentrations. Topical corticosteroids can make the disease worse and should be avoided. The duration of therapy may be substantially longer for chromoblastomycosis (months to years) compared to subcutaneous phaeohyphomycosis (weeks to months), although in immunocompromised individuals treatment may be even more prolonged.
Mycetoma
Mycetoma is caused by one of several different types of fungi (eumycetoma) and bacteria (actinomycetoma) that lead to progressively debilitating yet painless subcutaneous tumorlike lesions. The lesions usually manifest on the arms and legs but can occur anywhere.
Epidemiology—Little is known about the true global burden of mycetoma, but it occurs more frequently in low-income communities in rural areas.28 A retrospective review identified 19,494 cases published from 1876 to 2019, with cases reported in 102 countries.29 The countries with the highest numbers of cases are Sudan and Mexico, where there is more information on the distribution of the disease. Cases often are reported in what is known as the mycetoma belt (between latitudes 15° south and 30° north) but are increasingly identified outside this region.28 Young men aged 20 to 40 years are most commonly affected.
In the United States, mycetoma is uncommon, but clinicians can encounter locally acquired and travel-associated cases; hence, taking a good travel history is essential. One study specifically evaluating eumycetoma found a prevalence of 5.2 per 1,000,000 patients.8 Women and those aged 65 years or older had a higher incidence. Incidence was similar across US regions, but a higher incidence was reported in nonrural areas.8
Causative Organisms—More than 60 different species of fungi can cause eumycetoma; most cases are caused by Madurella mycetomatis, Trematosphaeria grisea (formerly Madurella grisea); Pseudallescheria boydii species complex, and Falciformispora (formerly Leptosphaeria) senegalensis.30 Actinomycetoma commonly is caused by Nocardia species (Nocardia brasiliensis, Nocardia asteroides, Nocardia otitidiscaviarum, Nocardia transvalensis, Nocardia harenae, and Nocardia takedensis), Streptomyces somaliensis, and Actinomadura species (Actinomadura madurae, Actinomadura pelletieri).31
Clinical Manifestations—Mycetoma is a chronic granulomatous disease with a progressive inflammatory reaction (Figures 4 and 5). Over the course of years, mycetoma progresses from small nodules to large, bone-invasive, mutilating lesions. Mycetoma manifests as a triad of painless firm subcutaneous masses, formation of multiple sinuses within the masses, and a purulent or seropurulent discharge containing sandlike visible particles (grains) that can be white, yellow, red, or black.28 Lesions usually are painless in early disease and are slowly progressive. Large lesion size, bone destruction, secondary bacterial infections, and actinomycetoma may lead to higher likelihood of pain.32


Diagnosis—Other conditions that could manifest with the same triad seen in mycetoma such as botryomycosis should be included in the differential. Other differential diagnoses include foreign body granuloma, filariasis, mycobacterial infection, skeletal tuberculosis, and yaws.
Proper treatment requires an accurate diagnosis that distinguishes actinomycetoma from eumycetoma.33 Culturing of grains obtained from deep lesion aspirates enables identification of the causative organism (Figure 6). The color of the grains may provide clues to their etiology: black grains are caused by fungus, red grains by a bacterium (A pelletieri), and pale (yellow or white) grains can be caused by either one.31Nocardia mycetoma grains are very small and usually cannot be appreciated with the naked eye. Histopathology of deep biopsy specimens (biopsy needle or surgical biopsy) stained with hematoxylin and eosin can diagnose actinomycetoma and eumycetoma. Punch biopsies often are not helpful, as the inflammatory mass is too deeply located. Deep surgical biopsy is preferred; however, species identification cannot be made without culture. Molecular tests for certain causative organisms of mycetoma have been developed but are not readily available.34,35 Currently, no serologic tests can diagnose mycetoma reliably. Ultrasonography can be used to diagnose mycetoma and, with appropriate training, distinguish between actinomycetoma and eumycetoma; it also can be combined with needle aspiration for taking grain samples.36

Treatment—Treatment of mycetoma depends on identification of the causal etiology and requires long-term and expensive drug regimens. It is not possible to determine the causative organism clinically. Actinomycetoma generally responds to medical treatment, and surgery rarely is needed. The current first-line treatment is co-trimoxazole (trimethoprim/sulfamethoxazole) in combination with amoxicillin and clavulanate acid or co-trimoxazole and amikacin for refractory disease; linezolid also may be a promising option for refractory disease.37
Eumycetoma is less responsive to medical therapies, and recurrence is common. Current recommended therapy is itraconazole for 9 to 12 months; however, cure rates ranging from 26% to 75% in combination with surgery have been reported, and fungi often can still be cultured from lesions posttreatment.38,39 Surgical excision often is used following 6 months of treatment with itraconazole to obtain better outcomes. Amputation may be required if the combination of antifungals and surgical excision fails. Fosravuconazole has shown promise in one clinical trial, but it is not approved in most countries, including the United States.39
Final Thoughts
Chromoblastomycosis, subcutaneous phaeohyphomycosis, and mycetoma can cause devastating disease. Patients with these conditions often are unable to carry out daily activities and experience stigma and discrimination. Limited diagnostic and treatment options hamper the ability of clinicians to respond appropriately to suspect and confirmed disease. Effectively examining the skin is the starting point for diagnosing and managing these diseases and can help clinicians to care for patients and prevent severe disease.
- Smith DJ, Soebono H, Parajuli N, et al. South-east Asia regional neglected tropical disease framework: improving control of mycetoma, chromoblastomycosis, and sporotrichosis. Lancet Reg Health Southeast Asia. 2025;35:100561. doi:10.1016/j.lansea.2025.100561
- Abbas M, Scolding PS, Yosif AA, et al. The disabling consequences of mycetoma. PLoS Negl Trop Dis. 2018;12:E0007019. doi:10.1371/journal.pntd.0007019
- Siregar GO, Harianja M, Rinonce HT, et al. Chromoblastomycosis: a case series from Sumba, eastern Indonesia. Clin Exp Dermatol. Published online March 8, 2025. doi:10.1093/ced/llaf111
- World Health Organization. Ending the neglect to attain the Sustainable Development Goals: a road map for neglected tropical diseases 2021-2030. Published January 28, 2021. Accessed May 5, 2024. https://www.who.int/publications/i/item/9789240010352
- Impact Global Health. The G-FINDER 2024 neglected disease R&D report. Impact Global Health. Published January 30, 2025. Accessed January 12, 2025. https://cdn.impactglobalhealth.org/media/G-FINDER%202024_Full%20report-1.pdf
- Queiroz-Telles F, de Hoog S, Santos DWCL, et al. Chromoblastomycosis. Clin Microbiol Rev. 2017;30:233-276. doi:10.1128/CMR.00032-16
- Santos DWCL, de Azevedo CMPS, Vicente VA, et al. The global burden of chromoblastomycosis. PLoS Negl Trop Dis. 2021;15:E0009611. doi:10.1371/journal.pntd.0009611
- Gold JAW, Smith DJ, Benedict K, et al. Epidemiology of implantation mycoses in the United States: an analysis of commercial insurance claims data, 2017 to 2021. J Am Acad Dermatol. 2023;89:427-430. doi:10.1016/j.jaad.2023.04.048
- Smith DJ, Queiroz-Telles F, Rabenja FR, et al. A global chromoblastomycosis strategy and development of the global chromoblastomycosis working group. PLoS Negl Trop Dis. 2024;18:e0012562. doi:10.1371/journal.pntd.0012562
- Heath CP, Sharma PC, Sontakke S, et al. The brief case: hidden in plain sight—exophiala jeanselmei subcutaneous phaeohyphomycosis of hand masquerading as a hematoma. J Clin Microbiol. 2024;62:E01068-24. doi:10.1128/jcm.01068-24
- Azevedo CMPS, Marques SG, Santos DWCL, et al. Squamous cell carcinoma derived from chronic chromoblastomycosis in Brazil. Clin Infect Dis. 2015;60:1500-1504. doi:10.1093/cid/civ104
- Sun J, Najafzadeh MJ, Gerrits van den Ende AHG, et al. Molecular characterization of pathogenic members of the genus Fonsecaea using multilocus analysis. PloS One. 2012;7:E41512. doi:10.1371/journal.pone.0041512
- Najafzadeh MJ, Sun J, Vicente V, et al. Fonsecaea nubica sp. nov, a new agent of human chromoblastomycosis revealed using molecular data. Med Mycol. 2010;48:800-806. doi:10.3109/13693780903503081
- Andrade TS, Castro LGM, Nunes RS, et al. Susceptibility of sequential Fonsecaea pedrosoi isolates from chromoblastomycosis patients to antifungal agents. Mycoses. 2004;47:216-221. doi:10.1111/j.1439-0507.2004.00984.x
- Smith DJ, Melhem MSC, Dirven J, et al. Establishment of epidemiological cutoff values for Fonsecaea pedrosoi, the primary etiologic agent of chromoblastomycosis, and eight antifungal medications. J Clin Microbiol. Published online April 4, 2025. doi:10.1128/jcm.01903-24
- Revankar SG, Sutton DA. Melanized fungi in human disease. Clin Microbiol Rev. 2010;23:884-928. doi:10.1128/CMR.00019-10
- de Sousa M da GT, Belda W, Spina R, et al. Topical application of imiquimod as a treatment for chromoblastomycosis. Clin Infect Dis. 2014;58:1734-1737. doi:10.1093/cid/ciu168
- Logan C, Singh M, Fox N, et al. Chromoblastomycosis treated with posaconazole and adjunctive imiquimod: lending innate immunity a helping hand. Open Forum Infect Dis. Published online March 14, 2023. doi:10.1093/ofid/ofad124
- Castro LGM, Pimentel ERA, Lacaz CS. Treatment of chromomycosis by cryosurgery with liquid nitrogen: 15 years’ experience. Int J Dermatol. 2003;42:408-412. doi:10.1046/j.1365-4362.2003.01532.x
- Tagami H, Ohi M, Aoshima T, et al. Topical heat therapy for cutaneous chromomycosis. Arch Dermatol. 1979;115:740-741.
- Lyon JP, Pedroso e Silva Azevedo C de M, Moreira LM, et al. Photodynamic antifungal therapy against chromoblastomycosis. Mycopathologia. 2011;172:293-297. doi:10.1007/s11046-011-9434-6
- Kinbara T, Fukushiro R, Eryu Y. Chromomycosis—report of two cases successfully treated with local heat therapy. Mykosen. 1982;25:689-694. doi:10.1111/j.1439-0507.1982.tb01944.x
- Yang Y, Hu Y, Zhang J, et al. A refractory case of chromoblastomycosis due to Fonsecaea monophora with improvement by photodynamic therapy. Med Mycol. 2012;50:649-653. doi:10.3109/13693786.2012.655258
- Sánchez-Cárdenas CD, Isa-Pimentel M, Arenas R. Phaeohyphomycosis: a review. Microbiol Res. 2023;14:1751-1763. doi:10.3390/microbiolres14040120
- Guillet J, Berkaoui I, Gargala G, et al. Cutaneous alternariosis. Mycopathologia. 2024;189:81. doi:10.1007/s11046-024-00888-5
- Wang X, Wang W, Lin Z, et al. CARD9 mutations linked to subcutaneous phaeohyphomycosis and TH17 cell deficiencies. J Allergy Clin Immunol. 2014;133:905-908. doi:10.1016/j.jaci.2013.09.033
- Revankar SG, Baddley JW, Chen SCA, et al. A mycoses study group international prospective study of phaeohyphomycosis: an analysis of 99 proven/probable cases. Open Forum Infect Dis. 2017;4:ofx200. doi:10.1093/ofid/ofx200
- Zijlstra EE, van de Sande WWJ, Welsh O, et al. Mycetoma: a unique neglected tropical disease. Lancet Infect Dis. 2016;16:100-112. doi:10.1016/S1473-3099(15)00359-X
- Emery D, Denning DW. The global distribution of actinomycetoma and eumycetoma. PLoS Negl Trop Dis. 2020;14:E0008397. doi:10.1371/journal.pntd.0008397
- van de Sande WWJ, Fahal AH. An updated list of eumycetoma causative agents and their differences in grain formation and treatment response. Clin Microbiol Rev. Published online May 2024. doi:10.1128/cmr.00034-23
- Nenoff P, van de Sande WWJ, Fahal AH, et al. Eumycetoma and actinomycetoma—an update on causative agents, epidemiology, pathogenesis, diagnostics and therapy. J Eur Acad Dermatol Venereol. 2015;29:1873-1883. doi:10.1111/jdv.13008
- El-Amin SO, El-Amin RO, El-Amin SM, et al. Painful mycetoma: a study to understand the risk factors in patients visiting the Mycetoma Research Centre (MRC) in Khartoum, Sudan. Trans R Soc Trop Med Hyg. 2025;119:145-151. doi:10.1093/trstmh/trae093
- Ahmed AA, van de Sande W, Fahal AH. Mycetoma laboratory diagnosis: review article. PLoS Negl Trop Dis. 2017;11:e0005638. doi:10.1371/journal.pntd.0005638
- Siddig EE, Ahmed A, Hassan OB, et al. Using a Madurella mycetomatis specific PCR on grains obtained via noninvasive fine needle aspirated material is more accurate than cytology. Mycoses. Published online February 5, 2023. doi:10.1111/myc.13572
- Konings M, Siddig E, Eadie K, et al. The development of a multiplex recombinase polymerase amplification reaction to detect the most common causative agents of eumycetoma. Eur J Clin Microbiol Infect Dis. Published online April 30, 2025. doi:10.1007/s10096-025-05134-4
- Siddig EE, El Had Bakhait O, El nour Hussein Bahar M, et al. Ultrasound-guided fine-needle aspiration cytology significantly improved mycetoma diagnosis. J Eur Acad Dermatol Venereol. 2022;36:1845-1850. doi:10.1111/jdv.18363
- Bonifaz A, García-Sotelo RS, Lumbán-Ramirez F, et al. Update on actinomycetoma treatment: linezolid in the treatment of actinomycetomas due to Nocardia spp and Actinomadura madurae resistant to conventional treatments. Expert Rev Anti Infect Ther. 2025;23:79-89. doi:10.1080/14787210.2024.2448723
- Chandler DJ, Bonifaz A, van de Sande WWJ. An update on the development of novel antifungal agents for eumycetoma. Front Pharmacol. 2023;14:1165273. doi:10.3389/fphar.2023.1165273
- Fahal AH, Siddig Ahmed E, Mubarak Bakhiet S, et al. Two dose levels of once-weekly fosravuconazole versus daily itraconazole, in combination with surgery, in patients with eumycetoma in Sudan: a randomised, double-blind, phase 2, proof-of-concept superiority trial. Lancet Infect Dis. 2024;24:1254-1265. doi:10.1016/S1473-3099(24)00404-3
Implantation mycoses such as chromoblastomycosis, subcutaneous phaeohyphomycosis, and mycetoma are a diverse group of fungal diseases that occur when a break in the skin allows the entry of the causative fungus. These diseases disproportionately affect individuals in low- and middle-income countries causing substantial disability, decreased quality of life, and severe social stigma.1-3 Timely diagnosis and appropriate treatment are critical.
Chromoblastomycosis and mycetoma are designated as neglected tropical diseases, but research to improve their management is sparse, even compared to other neglected tropical diseases.4,5 Since there are no global diagnostic and treatment guidelines to date, we outline steps to diagnose and manage chromoblastomycosis, subcutaneous phaeohyphomycosis, and mycetoma.
Chromoblastomycosis
Chromoblastomycosis is caused by dematiaceous fungi that typically affect the skin and subcutaneous tissue. Chromoblastomycosis is distinguished from subcutaneous phaeohyphomycosis by microscopically visualizing the characteristic thick-walled, single, or multicellular clusters of pigmented fungal cells (also known as medlar bodies, muriform cells, or sclerotic bodies).6 In phaeohyphomycosis, short hyphae and pseudohyphae plus some single cells typically are seen.
Epidemiology—Globally, the distribution and burden of chromoblastomycosis are relatively unknown. Infections are more common in tropical and subtropical areas but can be acquired anywhere. A literature review conducted in 2021 identified 7740 cases of chromoblastomycosis, mostly reported in South America, Africa, Central America and Mexico, and Asia.7 Most of the patients were male, and the median age was 52 years. One study found an incidence of 14.7 per 1,000,000 patients in the United States for both chromoblastomycosis and phaeohyphomycotic abscesses (which included both skin and brain abscesses).8 Most patients were aged 65 years or older, with a higher incidence in males. Geographically, the incidence was highest in the Northeast followed by the South; patients in rural areas also had higher incidence of disease.8
Causative Organisms—Causative species cannot reliably distinguish between chromoblastomycosis and subcutaneous phaeohyphomycosis, as some species overlap. Cladophialophora carrionii, Fonsecaea species, Phialophora verrucosa species complex, and Rhinocladiella aquaspersa most commonly cause chromoblastomycosis.9,10
Clinical Manifestations—Chromoblastomycosis initially manifests as a solitary erythematous macule at a site of trauma (often not recalled by the patient) that can evolve to a smooth pink papule and may progress to 1 of 5 morphologies: nodular, verrucous, tumorous, cicatricial, or plaque.6 Patients may present with more than one morphology, particularly in long-standing or advanced disease. Lesions commonly manifest on the arms and legs in otherwise healthy individuals in environments (eg, rural, agricultural) that have more opportunities for injury and exposure to the causative fungi. Affected individuals often have small black specks on the lesion surface that are visible with the naked eye.6
Diagnosis—Common differential diagnoses include cutaneous blastomycosis, fixed sporotrichosis, warty tuberculosis nocardiosis, cutaneous leishmaniasis, human papillomavirus (HPV) infection, podoconiosis, lymphatic filariasis, cutaneous tuberculosis, and psoriasis.6 Squamous cell carcinoma is both a differential diagnosis as well as a potential complication of the disease.11
Potassium hydroxide preparation with skin scapings or a biopsy from the lesion has high sensitivity and quick turnaround times. There often is a background histopathologic reaction of pseudoepitheliomatous hyperplasia. Examining samples taken from areas with the visible small black dots on the skin surface can increase the likelihood of detecting fungal elements (Figure 1). Clinicians also may choose to obtain a 6- to 8-mm deep skin biopsy from the lesion and splice it in half, with one sample sent for histopathology and the other for culture (Figure 2). Skin scrapings can be sent for culture instead. In the case of verrucous lesions, biopsy is preferred if feasible.


Treatment should not be delayed while awaiting the culture results if infection is otherwise confirmed by direct microscopy or histopathology. The treatment approach remains similar regardless of the causative species. If the culture results are positive, the causative genus can be identified by the microscopic morphology; however, molecular diagnostic tools are needed for accurate species identification.12,13
Antifungal Susceptibility Testing—For most dematiaceous fungi, interpreting minimum inhibitory concentrations (MICs) is challenging due to a lack of data from multicenter studies. One report examined sequential isolates of Fonsecaea pedrosoi and demonstrated both high MIC values and clinical resistance to itraconazole in some cases, likely from treatment pressure.14 Clinical Laboratory Standards Institute–approved epidemiologic cutoff values (ECVs) are established for F pedrosoi for commonly used antifungals including itraconazole (0.5 µg/mL), terbinafine (0.25 µg/mL), and posaconazole (0.5 µg/mL).15 Clinicians may choose to obtain sequential isolates for any causative fungi in recalcitrant disease to monitor for increases in MIC.
Management—In early-stage disease, excision of the skin nodule may be curative, although concomitant treatment for several months with an antifungal is advised. If antifungals are needed, itraconazole is the most commonly prescribed agent, typically at a dose of 100 to 200 mg twice daily. Terbinafine also has been used first-line at a dose of 250 to 500 mg per day. Voriconazole and posaconazole also may be suitable options for first-line or for refractory disease treatment. Fluconazole does not have good activity against dematiaceous fungi and should be avoided.16 Topical antifungals will not reach the site of infection in adequate concentrations. Topical corticosteroids can make the disease worse and should be avoided. The duration of therapy usually is several months, but many patients require years of therapy until resolution of lesions.
Clinicians can consider combination therapy with an antifungal and a topical immunomodulator such as imiquimod (applied topically 3 times per week); this combination can be considered in refractory disease and even upon initial diagnosis, especially in severe disease.17,18 Nonpharmacologic interventions such as cryotherapy, heat, and light-based therapies have been used, but outcome data are scarce.19-23
Subcutaneous Phaeohyphomycosis
Subcutaneous phaeohyphomycosis also is caused by dematiaceous fungi that typically affect the skin and subcutaneous tissue. Subcutaneous phaeohyphomycosis is distinguished from chromoblastomycosis by short hyphae and hyphal fragments usually seen microscopically instead of visualizing thick-walled, single, or multicellular clusters of pigmented fungal cells.6
Epidemiology—Globally, the burden and distribution of phaeohyphomycosis, including its cutaneous manifestations, are not well understood. Infections are more common in tropical and subtropical areas but can be acquired anywhere. Phaeohyphomycosis is a generic term used to describe infections caused by pigmented hyphal fungi that can manifest on the skin (subcutaneous phaeohyphomycosis) but also can affect deep structures including the brain (systemic phaeohyphomycosis).24
Causative Organisms—Alternaria, Bipolaris, Cladosporium, Curvularia, Exophiala, and Exserohilum species most commonly cause subcutaneous phaeohyphomycosis. Alternaria infections manifesting with skin lesions often are referred to as cutaneous alternariosis.25
Clinical Manifestations—The most common skin manifestation of phaeohyphomycosis is a subcutaneous cyst (cystic phaeohyphomycosis)(Figure 2). Subcutaneous phaeohyphomycosis also may manifest with nodules or plaques (Figure 3). Phaeohyphomycosis appears to occur more commonly in individuals who are immunosuppressed, those in whom T-cell function is affected, in congenital immunodeficiency states (eg, individuals with CARD9 mutations).26

Diagnosis—Culture is the gold standard for confirming phaeohyphomycosis.27 For cystic phaeohyphomycosis, clinicians can consider aspiration of the cyst for direct microscopic examination and culture. Histopathology may be utilized but can have lower sensitivity in showing dematiaceous hyphae and granulomatous inflammation; using the Masson-Fontana stain for melanin can be helpful. Molecular diagnostic tools including metagenomics applied directly to the tissue may be useful but are likely to have lower sensitivity than culture and require specialist diagnostic facilities.
Management—The approaches to managing chromoblastomycosis and subcutaneous phaeohyphomycosis are similar, though the preferred agents often differ. In early-stage disease, excision of the skin nodule may be curative, although concomitant treatment for several months with an antifungal is advised. In localized forms, itraconazole usually is used, but in those cases associated with immunodeficiency states, voriconazole may be necessary. Fluconazole does not have good activity against dematiaceous fungi and should be avoided.16 Topical antifungals will not reach the site of infection in adequate concentrations. Topical corticosteroids can make the disease worse and should be avoided. The duration of therapy may be substantially longer for chromoblastomycosis (months to years) compared to subcutaneous phaeohyphomycosis (weeks to months), although in immunocompromised individuals treatment may be even more prolonged.
Mycetoma
Mycetoma is caused by one of several different types of fungi (eumycetoma) and bacteria (actinomycetoma) that lead to progressively debilitating yet painless subcutaneous tumorlike lesions. The lesions usually manifest on the arms and legs but can occur anywhere.
Epidemiology—Little is known about the true global burden of mycetoma, but it occurs more frequently in low-income communities in rural areas.28 A retrospective review identified 19,494 cases published from 1876 to 2019, with cases reported in 102 countries.29 The countries with the highest numbers of cases are Sudan and Mexico, where there is more information on the distribution of the disease. Cases often are reported in what is known as the mycetoma belt (between latitudes 15° south and 30° north) but are increasingly identified outside this region.28 Young men aged 20 to 40 years are most commonly affected.
In the United States, mycetoma is uncommon, but clinicians can encounter locally acquired and travel-associated cases; hence, taking a good travel history is essential. One study specifically evaluating eumycetoma found a prevalence of 5.2 per 1,000,000 patients.8 Women and those aged 65 years or older had a higher incidence. Incidence was similar across US regions, but a higher incidence was reported in nonrural areas.8
Causative Organisms—More than 60 different species of fungi can cause eumycetoma; most cases are caused by Madurella mycetomatis, Trematosphaeria grisea (formerly Madurella grisea); Pseudallescheria boydii species complex, and Falciformispora (formerly Leptosphaeria) senegalensis.30 Actinomycetoma commonly is caused by Nocardia species (Nocardia brasiliensis, Nocardia asteroides, Nocardia otitidiscaviarum, Nocardia transvalensis, Nocardia harenae, and Nocardia takedensis), Streptomyces somaliensis, and Actinomadura species (Actinomadura madurae, Actinomadura pelletieri).31
Clinical Manifestations—Mycetoma is a chronic granulomatous disease with a progressive inflammatory reaction (Figures 4 and 5). Over the course of years, mycetoma progresses from small nodules to large, bone-invasive, mutilating lesions. Mycetoma manifests as a triad of painless firm subcutaneous masses, formation of multiple sinuses within the masses, and a purulent or seropurulent discharge containing sandlike visible particles (grains) that can be white, yellow, red, or black.28 Lesions usually are painless in early disease and are slowly progressive. Large lesion size, bone destruction, secondary bacterial infections, and actinomycetoma may lead to higher likelihood of pain.32


Diagnosis—Other conditions that could manifest with the same triad seen in mycetoma such as botryomycosis should be included in the differential. Other differential diagnoses include foreign body granuloma, filariasis, mycobacterial infection, skeletal tuberculosis, and yaws.
Proper treatment requires an accurate diagnosis that distinguishes actinomycetoma from eumycetoma.33 Culturing of grains obtained from deep lesion aspirates enables identification of the causative organism (Figure 6). The color of the grains may provide clues to their etiology: black grains are caused by fungus, red grains by a bacterium (A pelletieri), and pale (yellow or white) grains can be caused by either one.31Nocardia mycetoma grains are very small and usually cannot be appreciated with the naked eye. Histopathology of deep biopsy specimens (biopsy needle or surgical biopsy) stained with hematoxylin and eosin can diagnose actinomycetoma and eumycetoma. Punch biopsies often are not helpful, as the inflammatory mass is too deeply located. Deep surgical biopsy is preferred; however, species identification cannot be made without culture. Molecular tests for certain causative organisms of mycetoma have been developed but are not readily available.34,35 Currently, no serologic tests can diagnose mycetoma reliably. Ultrasonography can be used to diagnose mycetoma and, with appropriate training, distinguish between actinomycetoma and eumycetoma; it also can be combined with needle aspiration for taking grain samples.36

Treatment—Treatment of mycetoma depends on identification of the causal etiology and requires long-term and expensive drug regimens. It is not possible to determine the causative organism clinically. Actinomycetoma generally responds to medical treatment, and surgery rarely is needed. The current first-line treatment is co-trimoxazole (trimethoprim/sulfamethoxazole) in combination with amoxicillin and clavulanate acid or co-trimoxazole and amikacin for refractory disease; linezolid also may be a promising option for refractory disease.37
Eumycetoma is less responsive to medical therapies, and recurrence is common. Current recommended therapy is itraconazole for 9 to 12 months; however, cure rates ranging from 26% to 75% in combination with surgery have been reported, and fungi often can still be cultured from lesions posttreatment.38,39 Surgical excision often is used following 6 months of treatment with itraconazole to obtain better outcomes. Amputation may be required if the combination of antifungals and surgical excision fails. Fosravuconazole has shown promise in one clinical trial, but it is not approved in most countries, including the United States.39
Final Thoughts
Chromoblastomycosis, subcutaneous phaeohyphomycosis, and mycetoma can cause devastating disease. Patients with these conditions often are unable to carry out daily activities and experience stigma and discrimination. Limited diagnostic and treatment options hamper the ability of clinicians to respond appropriately to suspect and confirmed disease. Effectively examining the skin is the starting point for diagnosing and managing these diseases and can help clinicians to care for patients and prevent severe disease.
Implantation mycoses such as chromoblastomycosis, subcutaneous phaeohyphomycosis, and mycetoma are a diverse group of fungal diseases that occur when a break in the skin allows the entry of the causative fungus. These diseases disproportionately affect individuals in low- and middle-income countries causing substantial disability, decreased quality of life, and severe social stigma.1-3 Timely diagnosis and appropriate treatment are critical.
Chromoblastomycosis and mycetoma are designated as neglected tropical diseases, but research to improve their management is sparse, even compared to other neglected tropical diseases.4,5 Since there are no global diagnostic and treatment guidelines to date, we outline steps to diagnose and manage chromoblastomycosis, subcutaneous phaeohyphomycosis, and mycetoma.
Chromoblastomycosis
Chromoblastomycosis is caused by dematiaceous fungi that typically affect the skin and subcutaneous tissue. Chromoblastomycosis is distinguished from subcutaneous phaeohyphomycosis by microscopically visualizing the characteristic thick-walled, single, or multicellular clusters of pigmented fungal cells (also known as medlar bodies, muriform cells, or sclerotic bodies).6 In phaeohyphomycosis, short hyphae and pseudohyphae plus some single cells typically are seen.
Epidemiology—Globally, the distribution and burden of chromoblastomycosis are relatively unknown. Infections are more common in tropical and subtropical areas but can be acquired anywhere. A literature review conducted in 2021 identified 7740 cases of chromoblastomycosis, mostly reported in South America, Africa, Central America and Mexico, and Asia.7 Most of the patients were male, and the median age was 52 years. One study found an incidence of 14.7 per 1,000,000 patients in the United States for both chromoblastomycosis and phaeohyphomycotic abscesses (which included both skin and brain abscesses).8 Most patients were aged 65 years or older, with a higher incidence in males. Geographically, the incidence was highest in the Northeast followed by the South; patients in rural areas also had higher incidence of disease.8
Causative Organisms—Causative species cannot reliably distinguish between chromoblastomycosis and subcutaneous phaeohyphomycosis, as some species overlap. Cladophialophora carrionii, Fonsecaea species, Phialophora verrucosa species complex, and Rhinocladiella aquaspersa most commonly cause chromoblastomycosis.9,10
Clinical Manifestations—Chromoblastomycosis initially manifests as a solitary erythematous macule at a site of trauma (often not recalled by the patient) that can evolve to a smooth pink papule and may progress to 1 of 5 morphologies: nodular, verrucous, tumorous, cicatricial, or plaque.6 Patients may present with more than one morphology, particularly in long-standing or advanced disease. Lesions commonly manifest on the arms and legs in otherwise healthy individuals in environments (eg, rural, agricultural) that have more opportunities for injury and exposure to the causative fungi. Affected individuals often have small black specks on the lesion surface that are visible with the naked eye.6
Diagnosis—Common differential diagnoses include cutaneous blastomycosis, fixed sporotrichosis, warty tuberculosis nocardiosis, cutaneous leishmaniasis, human papillomavirus (HPV) infection, podoconiosis, lymphatic filariasis, cutaneous tuberculosis, and psoriasis.6 Squamous cell carcinoma is both a differential diagnosis as well as a potential complication of the disease.11
Potassium hydroxide preparation with skin scapings or a biopsy from the lesion has high sensitivity and quick turnaround times. There often is a background histopathologic reaction of pseudoepitheliomatous hyperplasia. Examining samples taken from areas with the visible small black dots on the skin surface can increase the likelihood of detecting fungal elements (Figure 1). Clinicians also may choose to obtain a 6- to 8-mm deep skin biopsy from the lesion and splice it in half, with one sample sent for histopathology and the other for culture (Figure 2). Skin scrapings can be sent for culture instead. In the case of verrucous lesions, biopsy is preferred if feasible.


Treatment should not be delayed while awaiting the culture results if infection is otherwise confirmed by direct microscopy or histopathology. The treatment approach remains similar regardless of the causative species. If the culture results are positive, the causative genus can be identified by the microscopic morphology; however, molecular diagnostic tools are needed for accurate species identification.12,13
Antifungal Susceptibility Testing—For most dematiaceous fungi, interpreting minimum inhibitory concentrations (MICs) is challenging due to a lack of data from multicenter studies. One report examined sequential isolates of Fonsecaea pedrosoi and demonstrated both high MIC values and clinical resistance to itraconazole in some cases, likely from treatment pressure.14 Clinical Laboratory Standards Institute–approved epidemiologic cutoff values (ECVs) are established for F pedrosoi for commonly used antifungals including itraconazole (0.5 µg/mL), terbinafine (0.25 µg/mL), and posaconazole (0.5 µg/mL).15 Clinicians may choose to obtain sequential isolates for any causative fungi in recalcitrant disease to monitor for increases in MIC.
Management—In early-stage disease, excision of the skin nodule may be curative, although concomitant treatment for several months with an antifungal is advised. If antifungals are needed, itraconazole is the most commonly prescribed agent, typically at a dose of 100 to 200 mg twice daily. Terbinafine also has been used first-line at a dose of 250 to 500 mg per day. Voriconazole and posaconazole also may be suitable options for first-line or for refractory disease treatment. Fluconazole does not have good activity against dematiaceous fungi and should be avoided.16 Topical antifungals will not reach the site of infection in adequate concentrations. Topical corticosteroids can make the disease worse and should be avoided. The duration of therapy usually is several months, but many patients require years of therapy until resolution of lesions.
Clinicians can consider combination therapy with an antifungal and a topical immunomodulator such as imiquimod (applied topically 3 times per week); this combination can be considered in refractory disease and even upon initial diagnosis, especially in severe disease.17,18 Nonpharmacologic interventions such as cryotherapy, heat, and light-based therapies have been used, but outcome data are scarce.19-23
Subcutaneous Phaeohyphomycosis
Subcutaneous phaeohyphomycosis also is caused by dematiaceous fungi that typically affect the skin and subcutaneous tissue. Subcutaneous phaeohyphomycosis is distinguished from chromoblastomycosis by short hyphae and hyphal fragments usually seen microscopically instead of visualizing thick-walled, single, or multicellular clusters of pigmented fungal cells.6
Epidemiology—Globally, the burden and distribution of phaeohyphomycosis, including its cutaneous manifestations, are not well understood. Infections are more common in tropical and subtropical areas but can be acquired anywhere. Phaeohyphomycosis is a generic term used to describe infections caused by pigmented hyphal fungi that can manifest on the skin (subcutaneous phaeohyphomycosis) but also can affect deep structures including the brain (systemic phaeohyphomycosis).24
Causative Organisms—Alternaria, Bipolaris, Cladosporium, Curvularia, Exophiala, and Exserohilum species most commonly cause subcutaneous phaeohyphomycosis. Alternaria infections manifesting with skin lesions often are referred to as cutaneous alternariosis.25
Clinical Manifestations—The most common skin manifestation of phaeohyphomycosis is a subcutaneous cyst (cystic phaeohyphomycosis)(Figure 2). Subcutaneous phaeohyphomycosis also may manifest with nodules or plaques (Figure 3). Phaeohyphomycosis appears to occur more commonly in individuals who are immunosuppressed, those in whom T-cell function is affected, in congenital immunodeficiency states (eg, individuals with CARD9 mutations).26

Diagnosis—Culture is the gold standard for confirming phaeohyphomycosis.27 For cystic phaeohyphomycosis, clinicians can consider aspiration of the cyst for direct microscopic examination and culture. Histopathology may be utilized but can have lower sensitivity in showing dematiaceous hyphae and granulomatous inflammation; using the Masson-Fontana stain for melanin can be helpful. Molecular diagnostic tools including metagenomics applied directly to the tissue may be useful but are likely to have lower sensitivity than culture and require specialist diagnostic facilities.
Management—The approaches to managing chromoblastomycosis and subcutaneous phaeohyphomycosis are similar, though the preferred agents often differ. In early-stage disease, excision of the skin nodule may be curative, although concomitant treatment for several months with an antifungal is advised. In localized forms, itraconazole usually is used, but in those cases associated with immunodeficiency states, voriconazole may be necessary. Fluconazole does not have good activity against dematiaceous fungi and should be avoided.16 Topical antifungals will not reach the site of infection in adequate concentrations. Topical corticosteroids can make the disease worse and should be avoided. The duration of therapy may be substantially longer for chromoblastomycosis (months to years) compared to subcutaneous phaeohyphomycosis (weeks to months), although in immunocompromised individuals treatment may be even more prolonged.
Mycetoma
Mycetoma is caused by one of several different types of fungi (eumycetoma) and bacteria (actinomycetoma) that lead to progressively debilitating yet painless subcutaneous tumorlike lesions. The lesions usually manifest on the arms and legs but can occur anywhere.
Epidemiology—Little is known about the true global burden of mycetoma, but it occurs more frequently in low-income communities in rural areas.28 A retrospective review identified 19,494 cases published from 1876 to 2019, with cases reported in 102 countries.29 The countries with the highest numbers of cases are Sudan and Mexico, where there is more information on the distribution of the disease. Cases often are reported in what is known as the mycetoma belt (between latitudes 15° south and 30° north) but are increasingly identified outside this region.28 Young men aged 20 to 40 years are most commonly affected.
In the United States, mycetoma is uncommon, but clinicians can encounter locally acquired and travel-associated cases; hence, taking a good travel history is essential. One study specifically evaluating eumycetoma found a prevalence of 5.2 per 1,000,000 patients.8 Women and those aged 65 years or older had a higher incidence. Incidence was similar across US regions, but a higher incidence was reported in nonrural areas.8
Causative Organisms—More than 60 different species of fungi can cause eumycetoma; most cases are caused by Madurella mycetomatis, Trematosphaeria grisea (formerly Madurella grisea); Pseudallescheria boydii species complex, and Falciformispora (formerly Leptosphaeria) senegalensis.30 Actinomycetoma commonly is caused by Nocardia species (Nocardia brasiliensis, Nocardia asteroides, Nocardia otitidiscaviarum, Nocardia transvalensis, Nocardia harenae, and Nocardia takedensis), Streptomyces somaliensis, and Actinomadura species (Actinomadura madurae, Actinomadura pelletieri).31
Clinical Manifestations—Mycetoma is a chronic granulomatous disease with a progressive inflammatory reaction (Figures 4 and 5). Over the course of years, mycetoma progresses from small nodules to large, bone-invasive, mutilating lesions. Mycetoma manifests as a triad of painless firm subcutaneous masses, formation of multiple sinuses within the masses, and a purulent or seropurulent discharge containing sandlike visible particles (grains) that can be white, yellow, red, or black.28 Lesions usually are painless in early disease and are slowly progressive. Large lesion size, bone destruction, secondary bacterial infections, and actinomycetoma may lead to higher likelihood of pain.32


Diagnosis—Other conditions that could manifest with the same triad seen in mycetoma such as botryomycosis should be included in the differential. Other differential diagnoses include foreign body granuloma, filariasis, mycobacterial infection, skeletal tuberculosis, and yaws.
Proper treatment requires an accurate diagnosis that distinguishes actinomycetoma from eumycetoma.33 Culturing of grains obtained from deep lesion aspirates enables identification of the causative organism (Figure 6). The color of the grains may provide clues to their etiology: black grains are caused by fungus, red grains by a bacterium (A pelletieri), and pale (yellow or white) grains can be caused by either one.31Nocardia mycetoma grains are very small and usually cannot be appreciated with the naked eye. Histopathology of deep biopsy specimens (biopsy needle or surgical biopsy) stained with hematoxylin and eosin can diagnose actinomycetoma and eumycetoma. Punch biopsies often are not helpful, as the inflammatory mass is too deeply located. Deep surgical biopsy is preferred; however, species identification cannot be made without culture. Molecular tests for certain causative organisms of mycetoma have been developed but are not readily available.34,35 Currently, no serologic tests can diagnose mycetoma reliably. Ultrasonography can be used to diagnose mycetoma and, with appropriate training, distinguish between actinomycetoma and eumycetoma; it also can be combined with needle aspiration for taking grain samples.36

Treatment—Treatment of mycetoma depends on identification of the causal etiology and requires long-term and expensive drug regimens. It is not possible to determine the causative organism clinically. Actinomycetoma generally responds to medical treatment, and surgery rarely is needed. The current first-line treatment is co-trimoxazole (trimethoprim/sulfamethoxazole) in combination with amoxicillin and clavulanate acid or co-trimoxazole and amikacin for refractory disease; linezolid also may be a promising option for refractory disease.37
Eumycetoma is less responsive to medical therapies, and recurrence is common. Current recommended therapy is itraconazole for 9 to 12 months; however, cure rates ranging from 26% to 75% in combination with surgery have been reported, and fungi often can still be cultured from lesions posttreatment.38,39 Surgical excision often is used following 6 months of treatment with itraconazole to obtain better outcomes. Amputation may be required if the combination of antifungals and surgical excision fails. Fosravuconazole has shown promise in one clinical trial, but it is not approved in most countries, including the United States.39
Final Thoughts
Chromoblastomycosis, subcutaneous phaeohyphomycosis, and mycetoma can cause devastating disease. Patients with these conditions often are unable to carry out daily activities and experience stigma and discrimination. Limited diagnostic and treatment options hamper the ability of clinicians to respond appropriately to suspect and confirmed disease. Effectively examining the skin is the starting point for diagnosing and managing these diseases and can help clinicians to care for patients and prevent severe disease.
- Smith DJ, Soebono H, Parajuli N, et al. South-east Asia regional neglected tropical disease framework: improving control of mycetoma, chromoblastomycosis, and sporotrichosis. Lancet Reg Health Southeast Asia. 2025;35:100561. doi:10.1016/j.lansea.2025.100561
- Abbas M, Scolding PS, Yosif AA, et al. The disabling consequences of mycetoma. PLoS Negl Trop Dis. 2018;12:E0007019. doi:10.1371/journal.pntd.0007019
- Siregar GO, Harianja M, Rinonce HT, et al. Chromoblastomycosis: a case series from Sumba, eastern Indonesia. Clin Exp Dermatol. Published online March 8, 2025. doi:10.1093/ced/llaf111
- World Health Organization. Ending the neglect to attain the Sustainable Development Goals: a road map for neglected tropical diseases 2021-2030. Published January 28, 2021. Accessed May 5, 2024. https://www.who.int/publications/i/item/9789240010352
- Impact Global Health. The G-FINDER 2024 neglected disease R&D report. Impact Global Health. Published January 30, 2025. Accessed January 12, 2025. https://cdn.impactglobalhealth.org/media/G-FINDER%202024_Full%20report-1.pdf
- Queiroz-Telles F, de Hoog S, Santos DWCL, et al. Chromoblastomycosis. Clin Microbiol Rev. 2017;30:233-276. doi:10.1128/CMR.00032-16
- Santos DWCL, de Azevedo CMPS, Vicente VA, et al. The global burden of chromoblastomycosis. PLoS Negl Trop Dis. 2021;15:E0009611. doi:10.1371/journal.pntd.0009611
- Gold JAW, Smith DJ, Benedict K, et al. Epidemiology of implantation mycoses in the United States: an analysis of commercial insurance claims data, 2017 to 2021. J Am Acad Dermatol. 2023;89:427-430. doi:10.1016/j.jaad.2023.04.048
- Smith DJ, Queiroz-Telles F, Rabenja FR, et al. A global chromoblastomycosis strategy and development of the global chromoblastomycosis working group. PLoS Negl Trop Dis. 2024;18:e0012562. doi:10.1371/journal.pntd.0012562
- Heath CP, Sharma PC, Sontakke S, et al. The brief case: hidden in plain sight—exophiala jeanselmei subcutaneous phaeohyphomycosis of hand masquerading as a hematoma. J Clin Microbiol. 2024;62:E01068-24. doi:10.1128/jcm.01068-24
- Azevedo CMPS, Marques SG, Santos DWCL, et al. Squamous cell carcinoma derived from chronic chromoblastomycosis in Brazil. Clin Infect Dis. 2015;60:1500-1504. doi:10.1093/cid/civ104
- Sun J, Najafzadeh MJ, Gerrits van den Ende AHG, et al. Molecular characterization of pathogenic members of the genus Fonsecaea using multilocus analysis. PloS One. 2012;7:E41512. doi:10.1371/journal.pone.0041512
- Najafzadeh MJ, Sun J, Vicente V, et al. Fonsecaea nubica sp. nov, a new agent of human chromoblastomycosis revealed using molecular data. Med Mycol. 2010;48:800-806. doi:10.3109/13693780903503081
- Andrade TS, Castro LGM, Nunes RS, et al. Susceptibility of sequential Fonsecaea pedrosoi isolates from chromoblastomycosis patients to antifungal agents. Mycoses. 2004;47:216-221. doi:10.1111/j.1439-0507.2004.00984.x
- Smith DJ, Melhem MSC, Dirven J, et al. Establishment of epidemiological cutoff values for Fonsecaea pedrosoi, the primary etiologic agent of chromoblastomycosis, and eight antifungal medications. J Clin Microbiol. Published online April 4, 2025. doi:10.1128/jcm.01903-24
- Revankar SG, Sutton DA. Melanized fungi in human disease. Clin Microbiol Rev. 2010;23:884-928. doi:10.1128/CMR.00019-10
- de Sousa M da GT, Belda W, Spina R, et al. Topical application of imiquimod as a treatment for chromoblastomycosis. Clin Infect Dis. 2014;58:1734-1737. doi:10.1093/cid/ciu168
- Logan C, Singh M, Fox N, et al. Chromoblastomycosis treated with posaconazole and adjunctive imiquimod: lending innate immunity a helping hand. Open Forum Infect Dis. Published online March 14, 2023. doi:10.1093/ofid/ofad124
- Castro LGM, Pimentel ERA, Lacaz CS. Treatment of chromomycosis by cryosurgery with liquid nitrogen: 15 years’ experience. Int J Dermatol. 2003;42:408-412. doi:10.1046/j.1365-4362.2003.01532.x
- Tagami H, Ohi M, Aoshima T, et al. Topical heat therapy for cutaneous chromomycosis. Arch Dermatol. 1979;115:740-741.
- Lyon JP, Pedroso e Silva Azevedo C de M, Moreira LM, et al. Photodynamic antifungal therapy against chromoblastomycosis. Mycopathologia. 2011;172:293-297. doi:10.1007/s11046-011-9434-6
- Kinbara T, Fukushiro R, Eryu Y. Chromomycosis—report of two cases successfully treated with local heat therapy. Mykosen. 1982;25:689-694. doi:10.1111/j.1439-0507.1982.tb01944.x
- Yang Y, Hu Y, Zhang J, et al. A refractory case of chromoblastomycosis due to Fonsecaea monophora with improvement by photodynamic therapy. Med Mycol. 2012;50:649-653. doi:10.3109/13693786.2012.655258
- Sánchez-Cárdenas CD, Isa-Pimentel M, Arenas R. Phaeohyphomycosis: a review. Microbiol Res. 2023;14:1751-1763. doi:10.3390/microbiolres14040120
- Guillet J, Berkaoui I, Gargala G, et al. Cutaneous alternariosis. Mycopathologia. 2024;189:81. doi:10.1007/s11046-024-00888-5
- Wang X, Wang W, Lin Z, et al. CARD9 mutations linked to subcutaneous phaeohyphomycosis and TH17 cell deficiencies. J Allergy Clin Immunol. 2014;133:905-908. doi:10.1016/j.jaci.2013.09.033
- Revankar SG, Baddley JW, Chen SCA, et al. A mycoses study group international prospective study of phaeohyphomycosis: an analysis of 99 proven/probable cases. Open Forum Infect Dis. 2017;4:ofx200. doi:10.1093/ofid/ofx200
- Zijlstra EE, van de Sande WWJ, Welsh O, et al. Mycetoma: a unique neglected tropical disease. Lancet Infect Dis. 2016;16:100-112. doi:10.1016/S1473-3099(15)00359-X
- Emery D, Denning DW. The global distribution of actinomycetoma and eumycetoma. PLoS Negl Trop Dis. 2020;14:E0008397. doi:10.1371/journal.pntd.0008397
- van de Sande WWJ, Fahal AH. An updated list of eumycetoma causative agents and their differences in grain formation and treatment response. Clin Microbiol Rev. Published online May 2024. doi:10.1128/cmr.00034-23
- Nenoff P, van de Sande WWJ, Fahal AH, et al. Eumycetoma and actinomycetoma—an update on causative agents, epidemiology, pathogenesis, diagnostics and therapy. J Eur Acad Dermatol Venereol. 2015;29:1873-1883. doi:10.1111/jdv.13008
- El-Amin SO, El-Amin RO, El-Amin SM, et al. Painful mycetoma: a study to understand the risk factors in patients visiting the Mycetoma Research Centre (MRC) in Khartoum, Sudan. Trans R Soc Trop Med Hyg. 2025;119:145-151. doi:10.1093/trstmh/trae093
- Ahmed AA, van de Sande W, Fahal AH. Mycetoma laboratory diagnosis: review article. PLoS Negl Trop Dis. 2017;11:e0005638. doi:10.1371/journal.pntd.0005638
- Siddig EE, Ahmed A, Hassan OB, et al. Using a Madurella mycetomatis specific PCR on grains obtained via noninvasive fine needle aspirated material is more accurate than cytology. Mycoses. Published online February 5, 2023. doi:10.1111/myc.13572
- Konings M, Siddig E, Eadie K, et al. The development of a multiplex recombinase polymerase amplification reaction to detect the most common causative agents of eumycetoma. Eur J Clin Microbiol Infect Dis. Published online April 30, 2025. doi:10.1007/s10096-025-05134-4
- Siddig EE, El Had Bakhait O, El nour Hussein Bahar M, et al. Ultrasound-guided fine-needle aspiration cytology significantly improved mycetoma diagnosis. J Eur Acad Dermatol Venereol. 2022;36:1845-1850. doi:10.1111/jdv.18363
- Bonifaz A, García-Sotelo RS, Lumbán-Ramirez F, et al. Update on actinomycetoma treatment: linezolid in the treatment of actinomycetomas due to Nocardia spp and Actinomadura madurae resistant to conventional treatments. Expert Rev Anti Infect Ther. 2025;23:79-89. doi:10.1080/14787210.2024.2448723
- Chandler DJ, Bonifaz A, van de Sande WWJ. An update on the development of novel antifungal agents for eumycetoma. Front Pharmacol. 2023;14:1165273. doi:10.3389/fphar.2023.1165273
- Fahal AH, Siddig Ahmed E, Mubarak Bakhiet S, et al. Two dose levels of once-weekly fosravuconazole versus daily itraconazole, in combination with surgery, in patients with eumycetoma in Sudan: a randomised, double-blind, phase 2, proof-of-concept superiority trial. Lancet Infect Dis. 2024;24:1254-1265. doi:10.1016/S1473-3099(24)00404-3
- Smith DJ, Soebono H, Parajuli N, et al. South-east Asia regional neglected tropical disease framework: improving control of mycetoma, chromoblastomycosis, and sporotrichosis. Lancet Reg Health Southeast Asia. 2025;35:100561. doi:10.1016/j.lansea.2025.100561
- Abbas M, Scolding PS, Yosif AA, et al. The disabling consequences of mycetoma. PLoS Negl Trop Dis. 2018;12:E0007019. doi:10.1371/journal.pntd.0007019
- Siregar GO, Harianja M, Rinonce HT, et al. Chromoblastomycosis: a case series from Sumba, eastern Indonesia. Clin Exp Dermatol. Published online March 8, 2025. doi:10.1093/ced/llaf111
- World Health Organization. Ending the neglect to attain the Sustainable Development Goals: a road map for neglected tropical diseases 2021-2030. Published January 28, 2021. Accessed May 5, 2024. https://www.who.int/publications/i/item/9789240010352
- Impact Global Health. The G-FINDER 2024 neglected disease R&D report. Impact Global Health. Published January 30, 2025. Accessed January 12, 2025. https://cdn.impactglobalhealth.org/media/G-FINDER%202024_Full%20report-1.pdf
- Queiroz-Telles F, de Hoog S, Santos DWCL, et al. Chromoblastomycosis. Clin Microbiol Rev. 2017;30:233-276. doi:10.1128/CMR.00032-16
- Santos DWCL, de Azevedo CMPS, Vicente VA, et al. The global burden of chromoblastomycosis. PLoS Negl Trop Dis. 2021;15:E0009611. doi:10.1371/journal.pntd.0009611
- Gold JAW, Smith DJ, Benedict K, et al. Epidemiology of implantation mycoses in the United States: an analysis of commercial insurance claims data, 2017 to 2021. J Am Acad Dermatol. 2023;89:427-430. doi:10.1016/j.jaad.2023.04.048
- Smith DJ, Queiroz-Telles F, Rabenja FR, et al. A global chromoblastomycosis strategy and development of the global chromoblastomycosis working group. PLoS Negl Trop Dis. 2024;18:e0012562. doi:10.1371/journal.pntd.0012562
- Heath CP, Sharma PC, Sontakke S, et al. The brief case: hidden in plain sight—exophiala jeanselmei subcutaneous phaeohyphomycosis of hand masquerading as a hematoma. J Clin Microbiol. 2024;62:E01068-24. doi:10.1128/jcm.01068-24
- Azevedo CMPS, Marques SG, Santos DWCL, et al. Squamous cell carcinoma derived from chronic chromoblastomycosis in Brazil. Clin Infect Dis. 2015;60:1500-1504. doi:10.1093/cid/civ104
- Sun J, Najafzadeh MJ, Gerrits van den Ende AHG, et al. Molecular characterization of pathogenic members of the genus Fonsecaea using multilocus analysis. PloS One. 2012;7:E41512. doi:10.1371/journal.pone.0041512
- Najafzadeh MJ, Sun J, Vicente V, et al. Fonsecaea nubica sp. nov, a new agent of human chromoblastomycosis revealed using molecular data. Med Mycol. 2010;48:800-806. doi:10.3109/13693780903503081
- Andrade TS, Castro LGM, Nunes RS, et al. Susceptibility of sequential Fonsecaea pedrosoi isolates from chromoblastomycosis patients to antifungal agents. Mycoses. 2004;47:216-221. doi:10.1111/j.1439-0507.2004.00984.x
- Smith DJ, Melhem MSC, Dirven J, et al. Establishment of epidemiological cutoff values for Fonsecaea pedrosoi, the primary etiologic agent of chromoblastomycosis, and eight antifungal medications. J Clin Microbiol. Published online April 4, 2025. doi:10.1128/jcm.01903-24
- Revankar SG, Sutton DA. Melanized fungi in human disease. Clin Microbiol Rev. 2010;23:884-928. doi:10.1128/CMR.00019-10
- de Sousa M da GT, Belda W, Spina R, et al. Topical application of imiquimod as a treatment for chromoblastomycosis. Clin Infect Dis. 2014;58:1734-1737. doi:10.1093/cid/ciu168
- Logan C, Singh M, Fox N, et al. Chromoblastomycosis treated with posaconazole and adjunctive imiquimod: lending innate immunity a helping hand. Open Forum Infect Dis. Published online March 14, 2023. doi:10.1093/ofid/ofad124
- Castro LGM, Pimentel ERA, Lacaz CS. Treatment of chromomycosis by cryosurgery with liquid nitrogen: 15 years’ experience. Int J Dermatol. 2003;42:408-412. doi:10.1046/j.1365-4362.2003.01532.x
- Tagami H, Ohi M, Aoshima T, et al. Topical heat therapy for cutaneous chromomycosis. Arch Dermatol. 1979;115:740-741.
- Lyon JP, Pedroso e Silva Azevedo C de M, Moreira LM, et al. Photodynamic antifungal therapy against chromoblastomycosis. Mycopathologia. 2011;172:293-297. doi:10.1007/s11046-011-9434-6
- Kinbara T, Fukushiro R, Eryu Y. Chromomycosis—report of two cases successfully treated with local heat therapy. Mykosen. 1982;25:689-694. doi:10.1111/j.1439-0507.1982.tb01944.x
- Yang Y, Hu Y, Zhang J, et al. A refractory case of chromoblastomycosis due to Fonsecaea monophora with improvement by photodynamic therapy. Med Mycol. 2012;50:649-653. doi:10.3109/13693786.2012.655258
- Sánchez-Cárdenas CD, Isa-Pimentel M, Arenas R. Phaeohyphomycosis: a review. Microbiol Res. 2023;14:1751-1763. doi:10.3390/microbiolres14040120
- Guillet J, Berkaoui I, Gargala G, et al. Cutaneous alternariosis. Mycopathologia. 2024;189:81. doi:10.1007/s11046-024-00888-5
- Wang X, Wang W, Lin Z, et al. CARD9 mutations linked to subcutaneous phaeohyphomycosis and TH17 cell deficiencies. J Allergy Clin Immunol. 2014;133:905-908. doi:10.1016/j.jaci.2013.09.033
- Revankar SG, Baddley JW, Chen SCA, et al. A mycoses study group international prospective study of phaeohyphomycosis: an analysis of 99 proven/probable cases. Open Forum Infect Dis. 2017;4:ofx200. doi:10.1093/ofid/ofx200
- Zijlstra EE, van de Sande WWJ, Welsh O, et al. Mycetoma: a unique neglected tropical disease. Lancet Infect Dis. 2016;16:100-112. doi:10.1016/S1473-3099(15)00359-X
- Emery D, Denning DW. The global distribution of actinomycetoma and eumycetoma. PLoS Negl Trop Dis. 2020;14:E0008397. doi:10.1371/journal.pntd.0008397
- van de Sande WWJ, Fahal AH. An updated list of eumycetoma causative agents and their differences in grain formation and treatment response. Clin Microbiol Rev. Published online May 2024. doi:10.1128/cmr.00034-23
- Nenoff P, van de Sande WWJ, Fahal AH, et al. Eumycetoma and actinomycetoma—an update on causative agents, epidemiology, pathogenesis, diagnostics and therapy. J Eur Acad Dermatol Venereol. 2015;29:1873-1883. doi:10.1111/jdv.13008
- El-Amin SO, El-Amin RO, El-Amin SM, et al. Painful mycetoma: a study to understand the risk factors in patients visiting the Mycetoma Research Centre (MRC) in Khartoum, Sudan. Trans R Soc Trop Med Hyg. 2025;119:145-151. doi:10.1093/trstmh/trae093
- Ahmed AA, van de Sande W, Fahal AH. Mycetoma laboratory diagnosis: review article. PLoS Negl Trop Dis. 2017;11:e0005638. doi:10.1371/journal.pntd.0005638
- Siddig EE, Ahmed A, Hassan OB, et al. Using a Madurella mycetomatis specific PCR on grains obtained via noninvasive fine needle aspirated material is more accurate than cytology. Mycoses. Published online February 5, 2023. doi:10.1111/myc.13572
- Konings M, Siddig E, Eadie K, et al. The development of a multiplex recombinase polymerase amplification reaction to detect the most common causative agents of eumycetoma. Eur J Clin Microbiol Infect Dis. Published online April 30, 2025. doi:10.1007/s10096-025-05134-4
- Siddig EE, El Had Bakhait O, El nour Hussein Bahar M, et al. Ultrasound-guided fine-needle aspiration cytology significantly improved mycetoma diagnosis. J Eur Acad Dermatol Venereol. 2022;36:1845-1850. doi:10.1111/jdv.18363
- Bonifaz A, García-Sotelo RS, Lumbán-Ramirez F, et al. Update on actinomycetoma treatment: linezolid in the treatment of actinomycetomas due to Nocardia spp and Actinomadura madurae resistant to conventional treatments. Expert Rev Anti Infect Ther. 2025;23:79-89. doi:10.1080/14787210.2024.2448723
- Chandler DJ, Bonifaz A, van de Sande WWJ. An update on the development of novel antifungal agents for eumycetoma. Front Pharmacol. 2023;14:1165273. doi:10.3389/fphar.2023.1165273
- Fahal AH, Siddig Ahmed E, Mubarak Bakhiet S, et al. Two dose levels of once-weekly fosravuconazole versus daily itraconazole, in combination with surgery, in patients with eumycetoma in Sudan: a randomised, double-blind, phase 2, proof-of-concept superiority trial. Lancet Infect Dis. 2024;24:1254-1265. doi:10.1016/S1473-3099(24)00404-3
Approach to Diagnosing and Managing Implantation Mycoses
Approach to Diagnosing and Managing Implantation Mycoses
Practice Points
- Chromoblastomycosis, subcutaneous phaeohyphomycosis, and mycetoma are implantation mycoses that cause substantial morbidity, decreased quality of life, and social stigma.
- Consider obtaining a biopsy of suspected chromoblastomycosis and subcutaneous phaeohyphomycosis to confirm infection while sending half of the sample for culture for organism identification.
- Distinguishing between actinomycetoma (caused by filamentous bacteria) and eumycetoma (caused by fungi) is critical for appropriate mycetoma treatment.
Measles Resurgence: A Dermatologist’s Guide
Measles Resurgence: A Dermatologist’s Guide
Measles, also known as rubeola, is a highly contagious paramyxovirus that has neared elimination in the United States since 2000 due to widespread adoption of the measles vaccine; however, measles recently has made a comeback, with outbreaks reported in more than 60 countries. In the United States, vaccine hesitancy coupled with decreasing vaccination rates, international travel to endemic areas, and decreased funding and resources for monitoring and immunization programs likely led to a re-emergence of measles cases.1,2 The resurgence of measles is troubling given its infectiousness and potential severity in at-risk populations. Since measles has a basic reproduction number of 12 to 18 (ie, 1 infected individual will on average infect 12 to 18 others3), it has the capacity to spread quickly. This is why, prior to the development of the measles vaccine in the 1960s, it was responsible for millions of deaths across the globe.
Prior to the introduction of the measles vaccine, both physicians and the public generally were aware of the signs and symptoms of measles due to its prevalence; however, since there have been so few cases in recent decades, images and descriptions of patients presenting with measles can be found only in textbooks, and many physicians are ill-prepared to diagnose the disease.4 In response to the recent surge in measles cases, dermatologists—who often are among the first medical professionals to encounter febrile patients with rashes—must be prepared to bridge this divide. Herein, we review the clinical signs, diagnostic approach, operational precautions, and public health responsibilities that dermatologists must relearn amid the current measles outbreak.
Background
Measles is primarily transmitted via respiratory droplets and may remain airborne for up to 2 hours.5 It also can be transmitted through direct contact with secretions such as mucus. Indirect transmission via fomites, while certainly plausible, is thought to be the least effective mechanism of transmission.6 Following exposure, the incubation period ranges from 7 to 21 days, during which the virus replicates asymptomatically before causing clinical disease.7 Herd immunity for measles requires 93% immunity in the population; public health agencies typically target greater than 95% immunity.8 Humans are the only reservoir for the measles virus, making eradication possible.
The road to eradication began with the introduction of the measles vaccine in 1963 and subsequent development of the combined measles-mumps-rubella (MMR) vaccine in 1971. As MMR is a live vaccine, 2 doses confer approximately 97% protection.9 The first dose is given at 12 to 15 months of age, and the second dose is given at 4 to 6 years of age. Immunity is considered lifelong, and the Centers for Disease Control and Prevention and the World Health Organization do not recommend routine measles boosters for individuals who have completed the primary 2-dose series.10,11
Widespread vaccination led to a dramatic reduction in incidence, with many countries eliminating measles infections.7 The United States declared measles eliminated in 2000, with confirmed cases between 2000 and 2020 ranging from 37 to 1282.12 Vaccination progress stalled in the late 1990s due to vaccine hesitancy resulting from (subsequently debunked) reports of an association between the MMR vaccine and autism.13 Despite efforts to correct this misinformation, many patients continue to espouse these concerns.
Recognizing Measles: Clinical Presentation
Measles, which most often manifests in childhood but also can occur in adults, follows a distinctive clinical course. The prodromal phase is characterized by high fever, cough, coryza (nasal congestion), and conjunctivitis— conjunctivitis—the 3 “Cs” that serve as early warning signs of the disease. Patients may develop small white macules on the buccal mucosa known as Koplik spots (phonetically the fourth “C”), which appear just before the rash. Three to 5 days after the onset of systemic symptoms, patients will develop a classic morbilliform exanthem. In some cases, the exanthem manifests on the head and neck (Figure 1)—first behind the ears and along the hairline, then spreading caudally to the trunk and extremities. The lesions may become confluent, with patients presenting with diffuse erythema. The exanthem fades over several days to weeks, often accompanied by superficial desquamation.14

Given the nonspecificity of the early symptoms of measles, a high index of suspicion is needed for patients presenting with a febrile illness and a morbilliform eruption (Figure 2). Consideration of MMR vaccination status, exposure history, and local outbreak patterns can help guide risk stratification and the need for testing. Immunocompromised individuals, including those receiving immunosuppressive therapies for dermatologic conditions, may present atypically, lacking the prototypical exanthem or displaying milder signs and further complicating the diagnosis.15 The differential diagnosis for measles includes a drug reaction or other viral exanthem, and a detailed history may help elucidate the culprit.

Evaluation and Diagnosis
Definitive diagnosis of measles relies on both molecular and serologic testing. Nasopharyngeal swabs for measles polymerase chain reaction testing are obtained using synthetic (noncotton) swabs placed in a viral transport medium. Serum samples also should be collected for measles IgM and IgG antibody testing. Importantly, measles is a reportable illness, and testing may be coordinated with local departments of health.
Determining a patient’s immune status may be important for certain populations. Patients with documented 2-dose MMR vaccination, positive measles IgG serology, or a prior confirmed measles infection are considered immune. While a positive measles IgG indicates immunity, a negative result in an exposed patient should prompt consideration of postexposure prophylaxis with intravenous immunoglobulin.
Many patients, specifically those presenting to dermatology, are taking immunomodulatory or immunosuppressive medications—a contraindication for vaccination with the live MMR vaccine. At the time of publication, there was a single reported case of a patient taking a tumor necrosis factor α inhibitor for rheumatoid arthritis who had acquired measles.16 While the benefits of titer assessment in patients who are starting or continuing immunomodulatory therapy are not known and currently it is not recommended by the Centers for Disease Control and Prevention, dermatologists might consider checking MMR titers and vaccinating (or referring for vaccination) nonimmune patients.17
Infection Control
Early identification of a suspected measles case is paramount. Patients in whom measles is a possibility should be isolated as quickly as possible, and the patient and accompanying caregivers should be masked. Clinical staff should don appropriate personal protective equipment, including an N95 mask. Coordination with the local department of health must occur as soon as measles is suspected.
If testing is an option in the outpatient setting, a nasopharyngeal viral swab and serologic titers can be obtained. If testing is not available on site, patients should be sent to appropriate care facilities; prenotification is critical to prevent nosocomial outbreaks. Patients should be encouraged to isolate and avoid public spaces and/or public transport for 4 days following development of an exanthem.18 Offices should develop clinical protocols for suspected measles cases with training for clinical and office staff.
Final Thoughts
As measles outbreaks become more prevalent, it is incumbent upon physicians to remind ourselves of the signs and symptoms of this largely eliminated disease so that we may pursue early detection and intervention strategies. The primary cutaneous manifestations of measles make dermatologists critical to early recognition and containment efforts. Dermatologists should prepare for the arrival of patients with measles by maintaining vigilance for the classic signs of the disease, implementing stringent isolation protocols, verifying patient immunity when appropriate, and partnering closely with public health authorities.
More broadly, efforts to contain and re-establish a paradigm for eliminating measles outbreaks must be pursued. Encouraging vaccination and developing programs to help combat misinformation surrounding vaccines are critical to this effort. In an era of vaccine hesitancy, measles is a multidisciplinary public health emergency. Dermatologists must remain ready.
- Bedford H, Elliman D. Measles rates are rising again. BMJ. 2024;384.
- Harris E. Measles outbreaks grow amid declining vaccination rates. JAMA. 2023;330:2242.
- Guerra FM, Bolotin S, Lim G, et al. The basic reproduction number (R0) of measles: a systematic review. Lancet Infect Dis. 2017;17:E420-E428.
- Swartz MK. Measles: public and professional education. J Pediatr Health Care. 2019;33:367-368.
- Centers for Disease Control and Prevention. Interim infection prevention and control recommendations for measles in healthcare settings. Accessed April 27, 2025. https://www.cdc.gov/infection-control/hcp/measles/
- Moss WJ, Griffin DE, Feinstone WH. Measles. In: Vaccines for Biodefense and Emerging and Neglected Diseases. Elsevier; 2009: 551-565.
- Moss WJ. Measles. Lancet. 2017;390:2490-2502.
- Maintain the vaccination coverage level of 2 doses of the MMR vaccine for children in kindergarten— IID04. Healthy People 2030 website. Accessed May 6, 2025. https://odphp.health.gov/healthypeople/objectives-and-data/browse-objectives/vaccination/maintain-vaccination-coverage-level-2-doses-mmr-vaccine-children-kindergarten-iid-04
- Franconeri L, Antona D, Cauchemez S, et al. Two-dose measles vaccine effectiveness remains high over time: a French observational study, 2017–2019. Vaccine. 2023;41:5797-5804.
- World Health Organization. Measles. Accessed May 8, 2025. https:// www.who.int/news-room/fact-sheets/detail/measles
- Centers for Disease Control and Prevention. Measles vaccine recommendations. Accessed May 8, 2025. https://www.cdc.gov/measles/hcp/vaccine-considerations/index.html
- Centers for Disease Control and Prevention. Measles cases and outbreaks. Accessed May 6, 2025. https://www.cdc.gov/measles/cases-outbreaks.html
- Dyer C. Lancet retracts Wakefield’s MMR paper. BMJ. 2010;340.
- Alves Graber EM, Andrade FJ, Bost W, et al. An update and review of measles for emergency physicians. J Emerg Med. 2020;58:610-615.
- Kaplan LJ, Daum RS, Smaron M, et al. Severe measles in immunocompromised patients. JAMA. 1992;267:1237-1241.
- Takahashi E, Kurosaka D, Yoshida K, et al. Onset of modified measles after etanercept treatment in rheumatoid arthritis. Japanese J Clin Immunol. 2010;33:37-41.
- Worth A, Waldman RA, Dieckhaus K, et al. Art of prevention: our approach to the measles-mumps-rubella vaccine in adult patients vaccinated against measles before 1968 on biologic therapy for the treatment of psoriasis. Int J Womens Dermatol. 2019;6:94.
- Centers for Disease Control and Prevention. Clinical overview of measles (rubeola). Accessed May 8, 2025. https://www.cdc.gov/measles/hcp/clinical-overview/index.html
Measles, also known as rubeola, is a highly contagious paramyxovirus that has neared elimination in the United States since 2000 due to widespread adoption of the measles vaccine; however, measles recently has made a comeback, with outbreaks reported in more than 60 countries. In the United States, vaccine hesitancy coupled with decreasing vaccination rates, international travel to endemic areas, and decreased funding and resources for monitoring and immunization programs likely led to a re-emergence of measles cases.1,2 The resurgence of measles is troubling given its infectiousness and potential severity in at-risk populations. Since measles has a basic reproduction number of 12 to 18 (ie, 1 infected individual will on average infect 12 to 18 others3), it has the capacity to spread quickly. This is why, prior to the development of the measles vaccine in the 1960s, it was responsible for millions of deaths across the globe.
Prior to the introduction of the measles vaccine, both physicians and the public generally were aware of the signs and symptoms of measles due to its prevalence; however, since there have been so few cases in recent decades, images and descriptions of patients presenting with measles can be found only in textbooks, and many physicians are ill-prepared to diagnose the disease.4 In response to the recent surge in measles cases, dermatologists—who often are among the first medical professionals to encounter febrile patients with rashes—must be prepared to bridge this divide. Herein, we review the clinical signs, diagnostic approach, operational precautions, and public health responsibilities that dermatologists must relearn amid the current measles outbreak.
Background
Measles is primarily transmitted via respiratory droplets and may remain airborne for up to 2 hours.5 It also can be transmitted through direct contact with secretions such as mucus. Indirect transmission via fomites, while certainly plausible, is thought to be the least effective mechanism of transmission.6 Following exposure, the incubation period ranges from 7 to 21 days, during which the virus replicates asymptomatically before causing clinical disease.7 Herd immunity for measles requires 93% immunity in the population; public health agencies typically target greater than 95% immunity.8 Humans are the only reservoir for the measles virus, making eradication possible.
The road to eradication began with the introduction of the measles vaccine in 1963 and subsequent development of the combined measles-mumps-rubella (MMR) vaccine in 1971. As MMR is a live vaccine, 2 doses confer approximately 97% protection.9 The first dose is given at 12 to 15 months of age, and the second dose is given at 4 to 6 years of age. Immunity is considered lifelong, and the Centers for Disease Control and Prevention and the World Health Organization do not recommend routine measles boosters for individuals who have completed the primary 2-dose series.10,11
Widespread vaccination led to a dramatic reduction in incidence, with many countries eliminating measles infections.7 The United States declared measles eliminated in 2000, with confirmed cases between 2000 and 2020 ranging from 37 to 1282.12 Vaccination progress stalled in the late 1990s due to vaccine hesitancy resulting from (subsequently debunked) reports of an association between the MMR vaccine and autism.13 Despite efforts to correct this misinformation, many patients continue to espouse these concerns.
Recognizing Measles: Clinical Presentation
Measles, which most often manifests in childhood but also can occur in adults, follows a distinctive clinical course. The prodromal phase is characterized by high fever, cough, coryza (nasal congestion), and conjunctivitis— conjunctivitis—the 3 “Cs” that serve as early warning signs of the disease. Patients may develop small white macules on the buccal mucosa known as Koplik spots (phonetically the fourth “C”), which appear just before the rash. Three to 5 days after the onset of systemic symptoms, patients will develop a classic morbilliform exanthem. In some cases, the exanthem manifests on the head and neck (Figure 1)—first behind the ears and along the hairline, then spreading caudally to the trunk and extremities. The lesions may become confluent, with patients presenting with diffuse erythema. The exanthem fades over several days to weeks, often accompanied by superficial desquamation.14

Given the nonspecificity of the early symptoms of measles, a high index of suspicion is needed for patients presenting with a febrile illness and a morbilliform eruption (Figure 2). Consideration of MMR vaccination status, exposure history, and local outbreak patterns can help guide risk stratification and the need for testing. Immunocompromised individuals, including those receiving immunosuppressive therapies for dermatologic conditions, may present atypically, lacking the prototypical exanthem or displaying milder signs and further complicating the diagnosis.15 The differential diagnosis for measles includes a drug reaction or other viral exanthem, and a detailed history may help elucidate the culprit.

Evaluation and Diagnosis
Definitive diagnosis of measles relies on both molecular and serologic testing. Nasopharyngeal swabs for measles polymerase chain reaction testing are obtained using synthetic (noncotton) swabs placed in a viral transport medium. Serum samples also should be collected for measles IgM and IgG antibody testing. Importantly, measles is a reportable illness, and testing may be coordinated with local departments of health.
Determining a patient’s immune status may be important for certain populations. Patients with documented 2-dose MMR vaccination, positive measles IgG serology, or a prior confirmed measles infection are considered immune. While a positive measles IgG indicates immunity, a negative result in an exposed patient should prompt consideration of postexposure prophylaxis with intravenous immunoglobulin.
Many patients, specifically those presenting to dermatology, are taking immunomodulatory or immunosuppressive medications—a contraindication for vaccination with the live MMR vaccine. At the time of publication, there was a single reported case of a patient taking a tumor necrosis factor α inhibitor for rheumatoid arthritis who had acquired measles.16 While the benefits of titer assessment in patients who are starting or continuing immunomodulatory therapy are not known and currently it is not recommended by the Centers for Disease Control and Prevention, dermatologists might consider checking MMR titers and vaccinating (or referring for vaccination) nonimmune patients.17
Infection Control
Early identification of a suspected measles case is paramount. Patients in whom measles is a possibility should be isolated as quickly as possible, and the patient and accompanying caregivers should be masked. Clinical staff should don appropriate personal protective equipment, including an N95 mask. Coordination with the local department of health must occur as soon as measles is suspected.
If testing is an option in the outpatient setting, a nasopharyngeal viral swab and serologic titers can be obtained. If testing is not available on site, patients should be sent to appropriate care facilities; prenotification is critical to prevent nosocomial outbreaks. Patients should be encouraged to isolate and avoid public spaces and/or public transport for 4 days following development of an exanthem.18 Offices should develop clinical protocols for suspected measles cases with training for clinical and office staff.
Final Thoughts
As measles outbreaks become more prevalent, it is incumbent upon physicians to remind ourselves of the signs and symptoms of this largely eliminated disease so that we may pursue early detection and intervention strategies. The primary cutaneous manifestations of measles make dermatologists critical to early recognition and containment efforts. Dermatologists should prepare for the arrival of patients with measles by maintaining vigilance for the classic signs of the disease, implementing stringent isolation protocols, verifying patient immunity when appropriate, and partnering closely with public health authorities.
More broadly, efforts to contain and re-establish a paradigm for eliminating measles outbreaks must be pursued. Encouraging vaccination and developing programs to help combat misinformation surrounding vaccines are critical to this effort. In an era of vaccine hesitancy, measles is a multidisciplinary public health emergency. Dermatologists must remain ready.
Measles, also known as rubeola, is a highly contagious paramyxovirus that has neared elimination in the United States since 2000 due to widespread adoption of the measles vaccine; however, measles recently has made a comeback, with outbreaks reported in more than 60 countries. In the United States, vaccine hesitancy coupled with decreasing vaccination rates, international travel to endemic areas, and decreased funding and resources for monitoring and immunization programs likely led to a re-emergence of measles cases.1,2 The resurgence of measles is troubling given its infectiousness and potential severity in at-risk populations. Since measles has a basic reproduction number of 12 to 18 (ie, 1 infected individual will on average infect 12 to 18 others3), it has the capacity to spread quickly. This is why, prior to the development of the measles vaccine in the 1960s, it was responsible for millions of deaths across the globe.
Prior to the introduction of the measles vaccine, both physicians and the public generally were aware of the signs and symptoms of measles due to its prevalence; however, since there have been so few cases in recent decades, images and descriptions of patients presenting with measles can be found only in textbooks, and many physicians are ill-prepared to diagnose the disease.4 In response to the recent surge in measles cases, dermatologists—who often are among the first medical professionals to encounter febrile patients with rashes—must be prepared to bridge this divide. Herein, we review the clinical signs, diagnostic approach, operational precautions, and public health responsibilities that dermatologists must relearn amid the current measles outbreak.
Background
Measles is primarily transmitted via respiratory droplets and may remain airborne for up to 2 hours.5 It also can be transmitted through direct contact with secretions such as mucus. Indirect transmission via fomites, while certainly plausible, is thought to be the least effective mechanism of transmission.6 Following exposure, the incubation period ranges from 7 to 21 days, during which the virus replicates asymptomatically before causing clinical disease.7 Herd immunity for measles requires 93% immunity in the population; public health agencies typically target greater than 95% immunity.8 Humans are the only reservoir for the measles virus, making eradication possible.
The road to eradication began with the introduction of the measles vaccine in 1963 and subsequent development of the combined measles-mumps-rubella (MMR) vaccine in 1971. As MMR is a live vaccine, 2 doses confer approximately 97% protection.9 The first dose is given at 12 to 15 months of age, and the second dose is given at 4 to 6 years of age. Immunity is considered lifelong, and the Centers for Disease Control and Prevention and the World Health Organization do not recommend routine measles boosters for individuals who have completed the primary 2-dose series.10,11
Widespread vaccination led to a dramatic reduction in incidence, with many countries eliminating measles infections.7 The United States declared measles eliminated in 2000, with confirmed cases between 2000 and 2020 ranging from 37 to 1282.12 Vaccination progress stalled in the late 1990s due to vaccine hesitancy resulting from (subsequently debunked) reports of an association between the MMR vaccine and autism.13 Despite efforts to correct this misinformation, many patients continue to espouse these concerns.
Recognizing Measles: Clinical Presentation
Measles, which most often manifests in childhood but also can occur in adults, follows a distinctive clinical course. The prodromal phase is characterized by high fever, cough, coryza (nasal congestion), and conjunctivitis— conjunctivitis—the 3 “Cs” that serve as early warning signs of the disease. Patients may develop small white macules on the buccal mucosa known as Koplik spots (phonetically the fourth “C”), which appear just before the rash. Three to 5 days after the onset of systemic symptoms, patients will develop a classic morbilliform exanthem. In some cases, the exanthem manifests on the head and neck (Figure 1)—first behind the ears and along the hairline, then spreading caudally to the trunk and extremities. The lesions may become confluent, with patients presenting with diffuse erythema. The exanthem fades over several days to weeks, often accompanied by superficial desquamation.14

Given the nonspecificity of the early symptoms of measles, a high index of suspicion is needed for patients presenting with a febrile illness and a morbilliform eruption (Figure 2). Consideration of MMR vaccination status, exposure history, and local outbreak patterns can help guide risk stratification and the need for testing. Immunocompromised individuals, including those receiving immunosuppressive therapies for dermatologic conditions, may present atypically, lacking the prototypical exanthem or displaying milder signs and further complicating the diagnosis.15 The differential diagnosis for measles includes a drug reaction or other viral exanthem, and a detailed history may help elucidate the culprit.

Evaluation and Diagnosis
Definitive diagnosis of measles relies on both molecular and serologic testing. Nasopharyngeal swabs for measles polymerase chain reaction testing are obtained using synthetic (noncotton) swabs placed in a viral transport medium. Serum samples also should be collected for measles IgM and IgG antibody testing. Importantly, measles is a reportable illness, and testing may be coordinated with local departments of health.
Determining a patient’s immune status may be important for certain populations. Patients with documented 2-dose MMR vaccination, positive measles IgG serology, or a prior confirmed measles infection are considered immune. While a positive measles IgG indicates immunity, a negative result in an exposed patient should prompt consideration of postexposure prophylaxis with intravenous immunoglobulin.
Many patients, specifically those presenting to dermatology, are taking immunomodulatory or immunosuppressive medications—a contraindication for vaccination with the live MMR vaccine. At the time of publication, there was a single reported case of a patient taking a tumor necrosis factor α inhibitor for rheumatoid arthritis who had acquired measles.16 While the benefits of titer assessment in patients who are starting or continuing immunomodulatory therapy are not known and currently it is not recommended by the Centers for Disease Control and Prevention, dermatologists might consider checking MMR titers and vaccinating (or referring for vaccination) nonimmune patients.17
Infection Control
Early identification of a suspected measles case is paramount. Patients in whom measles is a possibility should be isolated as quickly as possible, and the patient and accompanying caregivers should be masked. Clinical staff should don appropriate personal protective equipment, including an N95 mask. Coordination with the local department of health must occur as soon as measles is suspected.
If testing is an option in the outpatient setting, a nasopharyngeal viral swab and serologic titers can be obtained. If testing is not available on site, patients should be sent to appropriate care facilities; prenotification is critical to prevent nosocomial outbreaks. Patients should be encouraged to isolate and avoid public spaces and/or public transport for 4 days following development of an exanthem.18 Offices should develop clinical protocols for suspected measles cases with training for clinical and office staff.
Final Thoughts
As measles outbreaks become more prevalent, it is incumbent upon physicians to remind ourselves of the signs and symptoms of this largely eliminated disease so that we may pursue early detection and intervention strategies. The primary cutaneous manifestations of measles make dermatologists critical to early recognition and containment efforts. Dermatologists should prepare for the arrival of patients with measles by maintaining vigilance for the classic signs of the disease, implementing stringent isolation protocols, verifying patient immunity when appropriate, and partnering closely with public health authorities.
More broadly, efforts to contain and re-establish a paradigm for eliminating measles outbreaks must be pursued. Encouraging vaccination and developing programs to help combat misinformation surrounding vaccines are critical to this effort. In an era of vaccine hesitancy, measles is a multidisciplinary public health emergency. Dermatologists must remain ready.
- Bedford H, Elliman D. Measles rates are rising again. BMJ. 2024;384.
- Harris E. Measles outbreaks grow amid declining vaccination rates. JAMA. 2023;330:2242.
- Guerra FM, Bolotin S, Lim G, et al. The basic reproduction number (R0) of measles: a systematic review. Lancet Infect Dis. 2017;17:E420-E428.
- Swartz MK. Measles: public and professional education. J Pediatr Health Care. 2019;33:367-368.
- Centers for Disease Control and Prevention. Interim infection prevention and control recommendations for measles in healthcare settings. Accessed April 27, 2025. https://www.cdc.gov/infection-control/hcp/measles/
- Moss WJ, Griffin DE, Feinstone WH. Measles. In: Vaccines for Biodefense and Emerging and Neglected Diseases. Elsevier; 2009: 551-565.
- Moss WJ. Measles. Lancet. 2017;390:2490-2502.
- Maintain the vaccination coverage level of 2 doses of the MMR vaccine for children in kindergarten— IID04. Healthy People 2030 website. Accessed May 6, 2025. https://odphp.health.gov/healthypeople/objectives-and-data/browse-objectives/vaccination/maintain-vaccination-coverage-level-2-doses-mmr-vaccine-children-kindergarten-iid-04
- Franconeri L, Antona D, Cauchemez S, et al. Two-dose measles vaccine effectiveness remains high over time: a French observational study, 2017–2019. Vaccine. 2023;41:5797-5804.
- World Health Organization. Measles. Accessed May 8, 2025. https:// www.who.int/news-room/fact-sheets/detail/measles
- Centers for Disease Control and Prevention. Measles vaccine recommendations. Accessed May 8, 2025. https://www.cdc.gov/measles/hcp/vaccine-considerations/index.html
- Centers for Disease Control and Prevention. Measles cases and outbreaks. Accessed May 6, 2025. https://www.cdc.gov/measles/cases-outbreaks.html
- Dyer C. Lancet retracts Wakefield’s MMR paper. BMJ. 2010;340.
- Alves Graber EM, Andrade FJ, Bost W, et al. An update and review of measles for emergency physicians. J Emerg Med. 2020;58:610-615.
- Kaplan LJ, Daum RS, Smaron M, et al. Severe measles in immunocompromised patients. JAMA. 1992;267:1237-1241.
- Takahashi E, Kurosaka D, Yoshida K, et al. Onset of modified measles after etanercept treatment in rheumatoid arthritis. Japanese J Clin Immunol. 2010;33:37-41.
- Worth A, Waldman RA, Dieckhaus K, et al. Art of prevention: our approach to the measles-mumps-rubella vaccine in adult patients vaccinated against measles before 1968 on biologic therapy for the treatment of psoriasis. Int J Womens Dermatol. 2019;6:94.
- Centers for Disease Control and Prevention. Clinical overview of measles (rubeola). Accessed May 8, 2025. https://www.cdc.gov/measles/hcp/clinical-overview/index.html
- Bedford H, Elliman D. Measles rates are rising again. BMJ. 2024;384.
- Harris E. Measles outbreaks grow amid declining vaccination rates. JAMA. 2023;330:2242.
- Guerra FM, Bolotin S, Lim G, et al. The basic reproduction number (R0) of measles: a systematic review. Lancet Infect Dis. 2017;17:E420-E428.
- Swartz MK. Measles: public and professional education. J Pediatr Health Care. 2019;33:367-368.
- Centers for Disease Control and Prevention. Interim infection prevention and control recommendations for measles in healthcare settings. Accessed April 27, 2025. https://www.cdc.gov/infection-control/hcp/measles/
- Moss WJ, Griffin DE, Feinstone WH. Measles. In: Vaccines for Biodefense and Emerging and Neglected Diseases. Elsevier; 2009: 551-565.
- Moss WJ. Measles. Lancet. 2017;390:2490-2502.
- Maintain the vaccination coverage level of 2 doses of the MMR vaccine for children in kindergarten— IID04. Healthy People 2030 website. Accessed May 6, 2025. https://odphp.health.gov/healthypeople/objectives-and-data/browse-objectives/vaccination/maintain-vaccination-coverage-level-2-doses-mmr-vaccine-children-kindergarten-iid-04
- Franconeri L, Antona D, Cauchemez S, et al. Two-dose measles vaccine effectiveness remains high over time: a French observational study, 2017–2019. Vaccine. 2023;41:5797-5804.
- World Health Organization. Measles. Accessed May 8, 2025. https:// www.who.int/news-room/fact-sheets/detail/measles
- Centers for Disease Control and Prevention. Measles vaccine recommendations. Accessed May 8, 2025. https://www.cdc.gov/measles/hcp/vaccine-considerations/index.html
- Centers for Disease Control and Prevention. Measles cases and outbreaks. Accessed May 6, 2025. https://www.cdc.gov/measles/cases-outbreaks.html
- Dyer C. Lancet retracts Wakefield’s MMR paper. BMJ. 2010;340.
- Alves Graber EM, Andrade FJ, Bost W, et al. An update and review of measles for emergency physicians. J Emerg Med. 2020;58:610-615.
- Kaplan LJ, Daum RS, Smaron M, et al. Severe measles in immunocompromised patients. JAMA. 1992;267:1237-1241.
- Takahashi E, Kurosaka D, Yoshida K, et al. Onset of modified measles after etanercept treatment in rheumatoid arthritis. Japanese J Clin Immunol. 2010;33:37-41.
- Worth A, Waldman RA, Dieckhaus K, et al. Art of prevention: our approach to the measles-mumps-rubella vaccine in adult patients vaccinated against measles before 1968 on biologic therapy for the treatment of psoriasis. Int J Womens Dermatol. 2019;6:94.
- Centers for Disease Control and Prevention. Clinical overview of measles (rubeola). Accessed May 8, 2025. https://www.cdc.gov/measles/hcp/clinical-overview/index.html
Measles Resurgence: A Dermatologist’s Guide
Measles Resurgence: A Dermatologist’s Guide
The Rise of Antifungal-Resistant Dermatophyte Infections: What Dermatologists Need to Know
The Rise of Antifungal-Resistant Dermatophyte Infections: What Dermatologists Need to Know
Worldwide, it is estimated that up to 1 in 5 individuals will experience a dermatophyte infection (commonly called ringworm or tinea infection) in their lifetime.1 Historically, dermatophyte infections have been considered relatively minor conditions usually treated with short courses of topical antifungals.2 Oral antifungals historically were needed only for patients with nail or hair shaft infections or extensive cutaneous fungal infections, which typically occurred in immunosuppressed patients.2 However, the landscape is changing rapidly due to the global emergence of severe dermatophyte infections that frequently are resistant to first-line antifungal medications.3-5 In this article, we aimed to review the epidemiology of emerging dermatophyte infections and provide dermatologists with information needed for effective diagnosis and management.
Emergence of Trichophyton indotineae
In recent decades, public health officials and dermatologists have noted with concern the spread of the recently emerged dermatophyte species Trichophyton indotineae in South Asia.3,6 This species (previously known as Trichophyton mentagrophytes genotype VIII) usually is transmitted from person to person, either through direct skin-to-skin contact or by fomites.4,6 Potential sexual transmission of T indotineae infections also has been reported,7 and it is possible that animals may serve as reservoirs for this pathogen, although there are no known reports of direct spread from animals to humans.8,9 Major outbreaks of T indotineae are ongoing in South Asia, and cases have been documented in 6 continents.10-12 In the United States, most but not all cases have occurred in immigrants from or recently returned travelers to South Asia.6,13 The emergence and spread of T indotineae is hypothesized to be promoted by the misuse and overuse of topical antifungal products, particularly those containing combinations of potent corticosteroids with other antimicrobial drugs.14,15
Cutaneous manifestations of T indotineae infections tend to cover large body surface areas, recur frequently, and pose substantial treatment challenges.6,13,16 Several clinical presentations have been documented, including erythematous, scaly concentric plaques; papulosquamous lesions; pustular forms; and corticosteroid-modified disease (Figure 1).6,16 Affected patients seldom are immunocompromised and often have a history of multiple failed courses of topical or oral antifungals, including oral terbinafine.13 Many also have been prescribed topical corticosteroids or have used over-the-counter topical corticosteroids, which worsen the rash.17

Direct microscopy with potassium hydroxide could be used to confirm the diagnosis of dermatophyte infection, but it does not distinguish T indotineae from other dermatophyte species.2,6 Importantly, culture-based testing usually will misidentify T indotineae as other Trichophyton species such as the more common T mentagrophytes or Trichophyton interdigitale. Definitive identification of T indotineae requires advanced molecular techniques that are available only at select laboratories.6 Unfortunately, availability of such testing is limited (Table), and results may take several weeks; therefore, it is suggested that dermatologists who suspect T indotineae infections based on the patient’s history and clinical presentation begin antifungal treatment after confirmation of dermatophyte infection but not wait for definitive confirmation of the causative organism.16

Itraconazole is considered the first-line therapy for T indotineae infection, as terbinafine usually is ineffective due to mutations in the squalene epoxidase gene.16 Dermatologists should be aware that itraconazole is available in different formulations that can affect absorption. The oral solution has greater bioavailability and should be taken on an empty stomach, whereas the capsules are required to be taken with food for effective absorption; the capsules also should be taken with an acidic beverage such as orange juice. Dermatologists should carefully assess for drug-drug interactions when prescribing itraconazole, given its extensive interaction profile with numerous other medications. Patients may require treatment with itraconazole (100 mg/d or 200 mg/d) for a minimum of 6 to 8 weeks until complete clearance has been achieved and ideally a negative potassium hydroxide preparation of skin scrapings has been obtained. A longer treatment period (eg, ≥3 months) frequently is needed, and relapses are common.6,16,18 Regular follow-up is needed to monitor for infection clearance and recurrences. It is important to note that cases of itraconazole resistance have been reported, although this currently appears to be uncommon.19,20
Other Emerging Dermatophytes to Watch
Trichophyton rubrum is the most common cause of dermatophyte infections among humans,21 and cases of terbinafine-resistant T rubrum infections have been reported increasingly in the United States and Canada.5,22-24 Onychomycosis caused by terbinafine-resistant T rubrum has been documented, and patients may have infections that do not respond to terbinafine given at the standard dose and duration.22,23 Case reports have indicated successful treatment using itraconazole 200 mg/d and posaconazole 300 mg/d.5,23
Trichophyton mentagrophytes genotype VII (TMVII) is an emerging dermatophyte that recently has been reported as a cause of sexually transmitted dermatophyte infections in Europe and the United States primarily affecting men who have sex with men.25-27 Patients may present with pruritic, annular, scaly patches and plaques involving the trunk, groin, genital region, or face (Figure 2). Although closely related to T indotineae, TMVII differs in that it more often affects the genital region, generally is susceptible to terbinafine, and in the United States and Europe usually is not related to travel or immigration involving South Asia.26 Although TMVII has not been associated with antifungal resistance, awareness among dermatologists is important because patients may experience inflamed, painful, and persistent rashes that can lead to secondary bacterial infection or scarring, and physicians might mistake it for mimics including eczema or psoriasis.25,26

Importance of Judicious Antifungal Use
Optimizing the use of antifungals is critical to improving patient outcomes and preserving available treatment options.28,29 A retrospective analysis of commercial health insurance data estimated that topical antifungal prescriptions were potentially unnecessary for more than half of the more than 560,000 patients who were prescribed these medications in 2023. In this study, it also was observed that only 16% of patients prescribed a topical antifungal had received diagnostic testing, with low rates across specialties.30 This is concerning because even among board-certified dermatologists, incorrect diagnosis of suspected fungal skin infections can occur; in one survey-based study of board-certified dermatologists who were presented with dermatomycosis images, respondents categorized cases with greater than 75% accuracy in only 31% (4/13) of instances.31 Clotrimazole-betamethasone is among the most commonly prescribed topical antifungals in the United States,14,32 and 2 recent retrospective analyses highlighted that the majority of patients prescribed this medication did not receive any fungal diagnostic testing.33,34
Final Thoughts
In an era of emerging antifungal-resistant dermatophyte infections, it is important for dermatologists to educate nondermatologists about the importance of using diagnostic testing for suspected dermatophyte infections.14,28 Dermatologists also can educate nondermatologist colleagues on the importance of avoiding the use of topical combination antifungal/corticosteroid medications and referring for dermatologic evaluation when diagnoses are uncertain.33,34 Strategies for education by dermatologists could include giving workshops, creating educational materials, and fostering open communication about optimal treatment practices and referral parameters for suspected dermatophyte infections.
- Noble SL, Forbes RC, Stamm PL. Diagnosis and management of common tinea infections. Am Fam Physician. 1998;58:163-174, 177-168.
- Ely JW, Rosenfeld S, Seabury Stone M. Diagnosis and management of tinea infections. Am Fam Physician. 2014;90:702-710.
- Uhrlaß S, Verma SB, Gräser Y, et al. Trichophyton indotineae—an emerging pathogen causing recalcitrant dermatophytoses in India and worldwide—a multidimensional perspective. J Fungi (Basel). 2022;8:757. doi:10.3390/jof8070757
- Verma SB, Panda S, Nenoff P, et al. The unprecedented epidemic-like scenario of dermatophytosis in India: I. epidemiology, risk factors and clinical features. Indian J Dermatol Venereol Leprol. 2021;87:154-175.
- Chen E, Ghannoum M, Elewski BE. Treatment]resistant tinea corporis, a potential public health issue. Br J Dermatol. 2021;184:164-165.
- Caplan AS. Notes from the field: first reported US cases of tinea caused by Trichophyton indotineae—New York City, December 2021–March 2023. MMWR Morbidity and Mortality Weekly Report. 2023;72:536-537. doi:10.15585/mmwr.mm7219a4
- Spivack S, Gold JA, Lockhart SR, et al. Potential sexual transmission of antifungal-resistant Trichophyton indotineae. Emerg Infect Dis. 2024;30:807.
- Jabet A, Brun S, Normand AC, et al. Extensive dermatophytosis caused by terbinafine-resistant Trichophyton indotineae, France. Emerg Infect Dis. 2022;28:229-233.
- Thakur S, Spruijtenburg B, Abhishek, et al. Whole genome sequence analysis of terbinafine resistant and susceptible Trichophyton isolates from human and animal origin. Mycopathologia. 2025;190:13.
- Lockhart SR, Chowdhary A, Gold JA. The rapid emergence of antifungal-resistant human-pathogenic fungi. Nat Rev Microbiol. 2023;21:818-832.
- Mosam A, Shuping L, Naicker S, et al. A case of antifungal-resistant ringworm infection in KwaZulu-Natal Province, South Africa, caused by Trichophyton indotineae. Public Health Bulletin South Africa. Accessed April 4, 2025. https://www.phbsa.ac.za/wp-content/uploads/2023/12PHBSA-Ringworm-Article-2023.pdf
- Cañete-Gibas CF, Mele J, Patterson HP, et al. Terbinafine-resistant dermatophytes and the presence of Trichophyton indotineae in North America. J Clin Microbiol. 2023;61:E0056223
- Caplan AS, Todd GC, Zhu Y, et al. Clinical course, antifungal susceptibility, and genomic sequencing of Trichophyton indotineae. JAMA Dermatol. 2024;160:701-709. doi:10.1001/jamadermatol.2024.1126
- Benedict K. Topical antifungal prescribing for Medicare Part D beneficiaries—United States, 2021. MMWR Morb Mortal Wkly Rep. 2024;73:1-5.
- Verma SB. Emergence of recalcitrant dermatophytosis in India. Lancet Infect Dis. 2018;18:718-719.
- Khurana A, Sharath S, Sardana K, et al. Clinico-mycological and therapeutic updates on cutaneous dermatophytic infections in the era of Trichophyton indotineae. J Am Acad Dermatol. 2024;91:315-323. doi:10.1016/j.jaad.2024.03.024
- Verma S. Steroid modified tinea. BMJ. 2017;356:j973.
- Khurana A, Agarwal A, Agrawal D, et al. Effect of different itraconazole dosing regimens on cure rates, treatment duration, safety, and relapse rates in adult patients with tinea corporis/cruris: a randomized clinical trial. JAMA Dermatol. 2022;158:1269-1278.
- Burmester A, Hipler UC, Uhrlaß S, et al. Indian Trichophyton mentagrophytes squalene epoxidase erg1 double mutants show high proportion of combined fluconazole and terbinafine resistance. Mycoses. 2020;63:1175-1180.
- Bhuiyan MSI, Verma SB, Illigner GM, et al. Trichophyton mentagrophytes ITS genotype VIII/Trichophyton indotineae infection and antifungal resistance in Bangladesh. J Fungi (Basel). 2024;10:768. doi:10.3390 /jof10110768
- Hay RJ. Chapter 82: superficial mycoses. In: Ryan ET, Hill DR, Solomon T, et al, eds. Hunter’s Tropical Medicine and Emerging Infectious Diseases. 10th ed. Elsevier; 2020:648-652.
- Gupta AK, Cooper EA, Wang T, et al. Detection of squalene epoxidase mutations in United States patients with onychomycosis: implications for management. J Invest Dermatol. 2023;143:2476-2483.E2477.
- Hwang JK, Bakotic WL, Gold JA, et al. Isolation of terbinafine-resistant Trichophyton rubrum from onychomycosis patients who failed treatment at an academic center in New York, United States. J Fungi. 2023;9:710.
- Gu D, Hatch M, Ghannoum M, et al. Treatment-resistant dermatophytosis: a representative case highlighting an emerging public health threat. JAAD Case Rep. 2020;6:1153-1155.
- Jabet A, Dellière S, Seang S, et al. Sexually transmitted Trichophyton mentagrophytes genotype VII infection among men who have sex with men. Emerg Infect Dis. 2023;29:1411-1414.
- Zucker J, Caplan AS, Gunaratne SH, et al. Notes from the field: Trichophyton mentagrophytes genotype VII—New York City, April-July 2024. MMWR Morb Mortal Wkly Rep. 2024;73:985-988.
- Jabet A, Bérot V, Chiarabini T, et al. Trichophyton mentagrophytes ITS genotype VII infections among men who have sex with men in France: an ongoing phenomenon. J Eur Acad Dermatol Venereol. 2025;39:407-415.
- Caplan AS, Gold JA, Smith DJ, et al. Improving antifungal stewardship in dermatology in an era of emerging dermatophyte resistance. JAAD International. 2024;15:168-169.
- Elewski B. A call for antifungal stewardship. Br J Dermatol. 2020; 183:798-799.
- Gold JAW, Benedict K, Caplan AS, et al. High rates of potentially unnecessary topical antifungal prescribing in a large commercial health insurance claims database, United States. J Am Acad Dermatol. 2025:S0190-9622(25)00098-2. doi:10.1016/j.jaad.2025.01.022
- Yadgar RJ, Bhatia N, Friedman A. Cutaneous fungal infections are commonly misdiagnosed: a survey-based study. J Am Acad Dermatol. 2017;76:562-563.
- Flint ND, Rhoads JLW, Carlisle R, et al. The continued inappropriate use and overuse of combination topical clotrimazole-betamethasone. Dermatol Online J. 2021;27. doi:10.5070/D327854686
- Currie DW, Caplan AS, Benedict K, et al. Prescribing of clotrimazolebetamethasone dipropionate, a topical combination corticosteroidantifungal product, for Medicare part D beneficiaries, United States, 2016–2022. Antimicrob Steward Healthc Epidemiol. 2024;4:E174.
- Gold JA, Caplan AS, Benedict K, et al. Clotrimazole-betamethasone dipropionate prescribing for nonfungal skin conditions. JAMA Network Open. 2024;7:E2411721-E2411721.
Worldwide, it is estimated that up to 1 in 5 individuals will experience a dermatophyte infection (commonly called ringworm or tinea infection) in their lifetime.1 Historically, dermatophyte infections have been considered relatively minor conditions usually treated with short courses of topical antifungals.2 Oral antifungals historically were needed only for patients with nail or hair shaft infections or extensive cutaneous fungal infections, which typically occurred in immunosuppressed patients.2 However, the landscape is changing rapidly due to the global emergence of severe dermatophyte infections that frequently are resistant to first-line antifungal medications.3-5 In this article, we aimed to review the epidemiology of emerging dermatophyte infections and provide dermatologists with information needed for effective diagnosis and management.
Emergence of Trichophyton indotineae
In recent decades, public health officials and dermatologists have noted with concern the spread of the recently emerged dermatophyte species Trichophyton indotineae in South Asia.3,6 This species (previously known as Trichophyton mentagrophytes genotype VIII) usually is transmitted from person to person, either through direct skin-to-skin contact or by fomites.4,6 Potential sexual transmission of T indotineae infections also has been reported,7 and it is possible that animals may serve as reservoirs for this pathogen, although there are no known reports of direct spread from animals to humans.8,9 Major outbreaks of T indotineae are ongoing in South Asia, and cases have been documented in 6 continents.10-12 In the United States, most but not all cases have occurred in immigrants from or recently returned travelers to South Asia.6,13 The emergence and spread of T indotineae is hypothesized to be promoted by the misuse and overuse of topical antifungal products, particularly those containing combinations of potent corticosteroids with other antimicrobial drugs.14,15
Cutaneous manifestations of T indotineae infections tend to cover large body surface areas, recur frequently, and pose substantial treatment challenges.6,13,16 Several clinical presentations have been documented, including erythematous, scaly concentric plaques; papulosquamous lesions; pustular forms; and corticosteroid-modified disease (Figure 1).6,16 Affected patients seldom are immunocompromised and often have a history of multiple failed courses of topical or oral antifungals, including oral terbinafine.13 Many also have been prescribed topical corticosteroids or have used over-the-counter topical corticosteroids, which worsen the rash.17

Direct microscopy with potassium hydroxide could be used to confirm the diagnosis of dermatophyte infection, but it does not distinguish T indotineae from other dermatophyte species.2,6 Importantly, culture-based testing usually will misidentify T indotineae as other Trichophyton species such as the more common T mentagrophytes or Trichophyton interdigitale. Definitive identification of T indotineae requires advanced molecular techniques that are available only at select laboratories.6 Unfortunately, availability of such testing is limited (Table), and results may take several weeks; therefore, it is suggested that dermatologists who suspect T indotineae infections based on the patient’s history and clinical presentation begin antifungal treatment after confirmation of dermatophyte infection but not wait for definitive confirmation of the causative organism.16

Itraconazole is considered the first-line therapy for T indotineae infection, as terbinafine usually is ineffective due to mutations in the squalene epoxidase gene.16 Dermatologists should be aware that itraconazole is available in different formulations that can affect absorption. The oral solution has greater bioavailability and should be taken on an empty stomach, whereas the capsules are required to be taken with food for effective absorption; the capsules also should be taken with an acidic beverage such as orange juice. Dermatologists should carefully assess for drug-drug interactions when prescribing itraconazole, given its extensive interaction profile with numerous other medications. Patients may require treatment with itraconazole (100 mg/d or 200 mg/d) for a minimum of 6 to 8 weeks until complete clearance has been achieved and ideally a negative potassium hydroxide preparation of skin scrapings has been obtained. A longer treatment period (eg, ≥3 months) frequently is needed, and relapses are common.6,16,18 Regular follow-up is needed to monitor for infection clearance and recurrences. It is important to note that cases of itraconazole resistance have been reported, although this currently appears to be uncommon.19,20
Other Emerging Dermatophytes to Watch
Trichophyton rubrum is the most common cause of dermatophyte infections among humans,21 and cases of terbinafine-resistant T rubrum infections have been reported increasingly in the United States and Canada.5,22-24 Onychomycosis caused by terbinafine-resistant T rubrum has been documented, and patients may have infections that do not respond to terbinafine given at the standard dose and duration.22,23 Case reports have indicated successful treatment using itraconazole 200 mg/d and posaconazole 300 mg/d.5,23
Trichophyton mentagrophytes genotype VII (TMVII) is an emerging dermatophyte that recently has been reported as a cause of sexually transmitted dermatophyte infections in Europe and the United States primarily affecting men who have sex with men.25-27 Patients may present with pruritic, annular, scaly patches and plaques involving the trunk, groin, genital region, or face (Figure 2). Although closely related to T indotineae, TMVII differs in that it more often affects the genital region, generally is susceptible to terbinafine, and in the United States and Europe usually is not related to travel or immigration involving South Asia.26 Although TMVII has not been associated with antifungal resistance, awareness among dermatologists is important because patients may experience inflamed, painful, and persistent rashes that can lead to secondary bacterial infection or scarring, and physicians might mistake it for mimics including eczema or psoriasis.25,26

Importance of Judicious Antifungal Use
Optimizing the use of antifungals is critical to improving patient outcomes and preserving available treatment options.28,29 A retrospective analysis of commercial health insurance data estimated that topical antifungal prescriptions were potentially unnecessary for more than half of the more than 560,000 patients who were prescribed these medications in 2023. In this study, it also was observed that only 16% of patients prescribed a topical antifungal had received diagnostic testing, with low rates across specialties.30 This is concerning because even among board-certified dermatologists, incorrect diagnosis of suspected fungal skin infections can occur; in one survey-based study of board-certified dermatologists who were presented with dermatomycosis images, respondents categorized cases with greater than 75% accuracy in only 31% (4/13) of instances.31 Clotrimazole-betamethasone is among the most commonly prescribed topical antifungals in the United States,14,32 and 2 recent retrospective analyses highlighted that the majority of patients prescribed this medication did not receive any fungal diagnostic testing.33,34
Final Thoughts
In an era of emerging antifungal-resistant dermatophyte infections, it is important for dermatologists to educate nondermatologists about the importance of using diagnostic testing for suspected dermatophyte infections.14,28 Dermatologists also can educate nondermatologist colleagues on the importance of avoiding the use of topical combination antifungal/corticosteroid medications and referring for dermatologic evaluation when diagnoses are uncertain.33,34 Strategies for education by dermatologists could include giving workshops, creating educational materials, and fostering open communication about optimal treatment practices and referral parameters for suspected dermatophyte infections.
Worldwide, it is estimated that up to 1 in 5 individuals will experience a dermatophyte infection (commonly called ringworm or tinea infection) in their lifetime.1 Historically, dermatophyte infections have been considered relatively minor conditions usually treated with short courses of topical antifungals.2 Oral antifungals historically were needed only for patients with nail or hair shaft infections or extensive cutaneous fungal infections, which typically occurred in immunosuppressed patients.2 However, the landscape is changing rapidly due to the global emergence of severe dermatophyte infections that frequently are resistant to first-line antifungal medications.3-5 In this article, we aimed to review the epidemiology of emerging dermatophyte infections and provide dermatologists with information needed for effective diagnosis and management.
Emergence of Trichophyton indotineae
In recent decades, public health officials and dermatologists have noted with concern the spread of the recently emerged dermatophyte species Trichophyton indotineae in South Asia.3,6 This species (previously known as Trichophyton mentagrophytes genotype VIII) usually is transmitted from person to person, either through direct skin-to-skin contact or by fomites.4,6 Potential sexual transmission of T indotineae infections also has been reported,7 and it is possible that animals may serve as reservoirs for this pathogen, although there are no known reports of direct spread from animals to humans.8,9 Major outbreaks of T indotineae are ongoing in South Asia, and cases have been documented in 6 continents.10-12 In the United States, most but not all cases have occurred in immigrants from or recently returned travelers to South Asia.6,13 The emergence and spread of T indotineae is hypothesized to be promoted by the misuse and overuse of topical antifungal products, particularly those containing combinations of potent corticosteroids with other antimicrobial drugs.14,15
Cutaneous manifestations of T indotineae infections tend to cover large body surface areas, recur frequently, and pose substantial treatment challenges.6,13,16 Several clinical presentations have been documented, including erythematous, scaly concentric plaques; papulosquamous lesions; pustular forms; and corticosteroid-modified disease (Figure 1).6,16 Affected patients seldom are immunocompromised and often have a history of multiple failed courses of topical or oral antifungals, including oral terbinafine.13 Many also have been prescribed topical corticosteroids or have used over-the-counter topical corticosteroids, which worsen the rash.17

Direct microscopy with potassium hydroxide could be used to confirm the diagnosis of dermatophyte infection, but it does not distinguish T indotineae from other dermatophyte species.2,6 Importantly, culture-based testing usually will misidentify T indotineae as other Trichophyton species such as the more common T mentagrophytes or Trichophyton interdigitale. Definitive identification of T indotineae requires advanced molecular techniques that are available only at select laboratories.6 Unfortunately, availability of such testing is limited (Table), and results may take several weeks; therefore, it is suggested that dermatologists who suspect T indotineae infections based on the patient’s history and clinical presentation begin antifungal treatment after confirmation of dermatophyte infection but not wait for definitive confirmation of the causative organism.16

Itraconazole is considered the first-line therapy for T indotineae infection, as terbinafine usually is ineffective due to mutations in the squalene epoxidase gene.16 Dermatologists should be aware that itraconazole is available in different formulations that can affect absorption. The oral solution has greater bioavailability and should be taken on an empty stomach, whereas the capsules are required to be taken with food for effective absorption; the capsules also should be taken with an acidic beverage such as orange juice. Dermatologists should carefully assess for drug-drug interactions when prescribing itraconazole, given its extensive interaction profile with numerous other medications. Patients may require treatment with itraconazole (100 mg/d or 200 mg/d) for a minimum of 6 to 8 weeks until complete clearance has been achieved and ideally a negative potassium hydroxide preparation of skin scrapings has been obtained. A longer treatment period (eg, ≥3 months) frequently is needed, and relapses are common.6,16,18 Regular follow-up is needed to monitor for infection clearance and recurrences. It is important to note that cases of itraconazole resistance have been reported, although this currently appears to be uncommon.19,20
Other Emerging Dermatophytes to Watch
Trichophyton rubrum is the most common cause of dermatophyte infections among humans,21 and cases of terbinafine-resistant T rubrum infections have been reported increasingly in the United States and Canada.5,22-24 Onychomycosis caused by terbinafine-resistant T rubrum has been documented, and patients may have infections that do not respond to terbinafine given at the standard dose and duration.22,23 Case reports have indicated successful treatment using itraconazole 200 mg/d and posaconazole 300 mg/d.5,23
Trichophyton mentagrophytes genotype VII (TMVII) is an emerging dermatophyte that recently has been reported as a cause of sexually transmitted dermatophyte infections in Europe and the United States primarily affecting men who have sex with men.25-27 Patients may present with pruritic, annular, scaly patches and plaques involving the trunk, groin, genital region, or face (Figure 2). Although closely related to T indotineae, TMVII differs in that it more often affects the genital region, generally is susceptible to terbinafine, and in the United States and Europe usually is not related to travel or immigration involving South Asia.26 Although TMVII has not been associated with antifungal resistance, awareness among dermatologists is important because patients may experience inflamed, painful, and persistent rashes that can lead to secondary bacterial infection or scarring, and physicians might mistake it for mimics including eczema or psoriasis.25,26

Importance of Judicious Antifungal Use
Optimizing the use of antifungals is critical to improving patient outcomes and preserving available treatment options.28,29 A retrospective analysis of commercial health insurance data estimated that topical antifungal prescriptions were potentially unnecessary for more than half of the more than 560,000 patients who were prescribed these medications in 2023. In this study, it also was observed that only 16% of patients prescribed a topical antifungal had received diagnostic testing, with low rates across specialties.30 This is concerning because even among board-certified dermatologists, incorrect diagnosis of suspected fungal skin infections can occur; in one survey-based study of board-certified dermatologists who were presented with dermatomycosis images, respondents categorized cases with greater than 75% accuracy in only 31% (4/13) of instances.31 Clotrimazole-betamethasone is among the most commonly prescribed topical antifungals in the United States,14,32 and 2 recent retrospective analyses highlighted that the majority of patients prescribed this medication did not receive any fungal diagnostic testing.33,34
Final Thoughts
In an era of emerging antifungal-resistant dermatophyte infections, it is important for dermatologists to educate nondermatologists about the importance of using diagnostic testing for suspected dermatophyte infections.14,28 Dermatologists also can educate nondermatologist colleagues on the importance of avoiding the use of topical combination antifungal/corticosteroid medications and referring for dermatologic evaluation when diagnoses are uncertain.33,34 Strategies for education by dermatologists could include giving workshops, creating educational materials, and fostering open communication about optimal treatment practices and referral parameters for suspected dermatophyte infections.
- Noble SL, Forbes RC, Stamm PL. Diagnosis and management of common tinea infections. Am Fam Physician. 1998;58:163-174, 177-168.
- Ely JW, Rosenfeld S, Seabury Stone M. Diagnosis and management of tinea infections. Am Fam Physician. 2014;90:702-710.
- Uhrlaß S, Verma SB, Gräser Y, et al. Trichophyton indotineae—an emerging pathogen causing recalcitrant dermatophytoses in India and worldwide—a multidimensional perspective. J Fungi (Basel). 2022;8:757. doi:10.3390/jof8070757
- Verma SB, Panda S, Nenoff P, et al. The unprecedented epidemic-like scenario of dermatophytosis in India: I. epidemiology, risk factors and clinical features. Indian J Dermatol Venereol Leprol. 2021;87:154-175.
- Chen E, Ghannoum M, Elewski BE. Treatment]resistant tinea corporis, a potential public health issue. Br J Dermatol. 2021;184:164-165.
- Caplan AS. Notes from the field: first reported US cases of tinea caused by Trichophyton indotineae—New York City, December 2021–March 2023. MMWR Morbidity and Mortality Weekly Report. 2023;72:536-537. doi:10.15585/mmwr.mm7219a4
- Spivack S, Gold JA, Lockhart SR, et al. Potential sexual transmission of antifungal-resistant Trichophyton indotineae. Emerg Infect Dis. 2024;30:807.
- Jabet A, Brun S, Normand AC, et al. Extensive dermatophytosis caused by terbinafine-resistant Trichophyton indotineae, France. Emerg Infect Dis. 2022;28:229-233.
- Thakur S, Spruijtenburg B, Abhishek, et al. Whole genome sequence analysis of terbinafine resistant and susceptible Trichophyton isolates from human and animal origin. Mycopathologia. 2025;190:13.
- Lockhart SR, Chowdhary A, Gold JA. The rapid emergence of antifungal-resistant human-pathogenic fungi. Nat Rev Microbiol. 2023;21:818-832.
- Mosam A, Shuping L, Naicker S, et al. A case of antifungal-resistant ringworm infection in KwaZulu-Natal Province, South Africa, caused by Trichophyton indotineae. Public Health Bulletin South Africa. Accessed April 4, 2025. https://www.phbsa.ac.za/wp-content/uploads/2023/12PHBSA-Ringworm-Article-2023.pdf
- Cañete-Gibas CF, Mele J, Patterson HP, et al. Terbinafine-resistant dermatophytes and the presence of Trichophyton indotineae in North America. J Clin Microbiol. 2023;61:E0056223
- Caplan AS, Todd GC, Zhu Y, et al. Clinical course, antifungal susceptibility, and genomic sequencing of Trichophyton indotineae. JAMA Dermatol. 2024;160:701-709. doi:10.1001/jamadermatol.2024.1126
- Benedict K. Topical antifungal prescribing for Medicare Part D beneficiaries—United States, 2021. MMWR Morb Mortal Wkly Rep. 2024;73:1-5.
- Verma SB. Emergence of recalcitrant dermatophytosis in India. Lancet Infect Dis. 2018;18:718-719.
- Khurana A, Sharath S, Sardana K, et al. Clinico-mycological and therapeutic updates on cutaneous dermatophytic infections in the era of Trichophyton indotineae. J Am Acad Dermatol. 2024;91:315-323. doi:10.1016/j.jaad.2024.03.024
- Verma S. Steroid modified tinea. BMJ. 2017;356:j973.
- Khurana A, Agarwal A, Agrawal D, et al. Effect of different itraconazole dosing regimens on cure rates, treatment duration, safety, and relapse rates in adult patients with tinea corporis/cruris: a randomized clinical trial. JAMA Dermatol. 2022;158:1269-1278.
- Burmester A, Hipler UC, Uhrlaß S, et al. Indian Trichophyton mentagrophytes squalene epoxidase erg1 double mutants show high proportion of combined fluconazole and terbinafine resistance. Mycoses. 2020;63:1175-1180.
- Bhuiyan MSI, Verma SB, Illigner GM, et al. Trichophyton mentagrophytes ITS genotype VIII/Trichophyton indotineae infection and antifungal resistance in Bangladesh. J Fungi (Basel). 2024;10:768. doi:10.3390 /jof10110768
- Hay RJ. Chapter 82: superficial mycoses. In: Ryan ET, Hill DR, Solomon T, et al, eds. Hunter’s Tropical Medicine and Emerging Infectious Diseases. 10th ed. Elsevier; 2020:648-652.
- Gupta AK, Cooper EA, Wang T, et al. Detection of squalene epoxidase mutations in United States patients with onychomycosis: implications for management. J Invest Dermatol. 2023;143:2476-2483.E2477.
- Hwang JK, Bakotic WL, Gold JA, et al. Isolation of terbinafine-resistant Trichophyton rubrum from onychomycosis patients who failed treatment at an academic center in New York, United States. J Fungi. 2023;9:710.
- Gu D, Hatch M, Ghannoum M, et al. Treatment-resistant dermatophytosis: a representative case highlighting an emerging public health threat. JAAD Case Rep. 2020;6:1153-1155.
- Jabet A, Dellière S, Seang S, et al. Sexually transmitted Trichophyton mentagrophytes genotype VII infection among men who have sex with men. Emerg Infect Dis. 2023;29:1411-1414.
- Zucker J, Caplan AS, Gunaratne SH, et al. Notes from the field: Trichophyton mentagrophytes genotype VII—New York City, April-July 2024. MMWR Morb Mortal Wkly Rep. 2024;73:985-988.
- Jabet A, Bérot V, Chiarabini T, et al. Trichophyton mentagrophytes ITS genotype VII infections among men who have sex with men in France: an ongoing phenomenon. J Eur Acad Dermatol Venereol. 2025;39:407-415.
- Caplan AS, Gold JA, Smith DJ, et al. Improving antifungal stewardship in dermatology in an era of emerging dermatophyte resistance. JAAD International. 2024;15:168-169.
- Elewski B. A call for antifungal stewardship. Br J Dermatol. 2020; 183:798-799.
- Gold JAW, Benedict K, Caplan AS, et al. High rates of potentially unnecessary topical antifungal prescribing in a large commercial health insurance claims database, United States. J Am Acad Dermatol. 2025:S0190-9622(25)00098-2. doi:10.1016/j.jaad.2025.01.022
- Yadgar RJ, Bhatia N, Friedman A. Cutaneous fungal infections are commonly misdiagnosed: a survey-based study. J Am Acad Dermatol. 2017;76:562-563.
- Flint ND, Rhoads JLW, Carlisle R, et al. The continued inappropriate use and overuse of combination topical clotrimazole-betamethasone. Dermatol Online J. 2021;27. doi:10.5070/D327854686
- Currie DW, Caplan AS, Benedict K, et al. Prescribing of clotrimazolebetamethasone dipropionate, a topical combination corticosteroidantifungal product, for Medicare part D beneficiaries, United States, 2016–2022. Antimicrob Steward Healthc Epidemiol. 2024;4:E174.
- Gold JA, Caplan AS, Benedict K, et al. Clotrimazole-betamethasone dipropionate prescribing for nonfungal skin conditions. JAMA Network Open. 2024;7:E2411721-E2411721.
- Noble SL, Forbes RC, Stamm PL. Diagnosis and management of common tinea infections. Am Fam Physician. 1998;58:163-174, 177-168.
- Ely JW, Rosenfeld S, Seabury Stone M. Diagnosis and management of tinea infections. Am Fam Physician. 2014;90:702-710.
- Uhrlaß S, Verma SB, Gräser Y, et al. Trichophyton indotineae—an emerging pathogen causing recalcitrant dermatophytoses in India and worldwide—a multidimensional perspective. J Fungi (Basel). 2022;8:757. doi:10.3390/jof8070757
- Verma SB, Panda S, Nenoff P, et al. The unprecedented epidemic-like scenario of dermatophytosis in India: I. epidemiology, risk factors and clinical features. Indian J Dermatol Venereol Leprol. 2021;87:154-175.
- Chen E, Ghannoum M, Elewski BE. Treatment]resistant tinea corporis, a potential public health issue. Br J Dermatol. 2021;184:164-165.
- Caplan AS. Notes from the field: first reported US cases of tinea caused by Trichophyton indotineae—New York City, December 2021–March 2023. MMWR Morbidity and Mortality Weekly Report. 2023;72:536-537. doi:10.15585/mmwr.mm7219a4
- Spivack S, Gold JA, Lockhart SR, et al. Potential sexual transmission of antifungal-resistant Trichophyton indotineae. Emerg Infect Dis. 2024;30:807.
- Jabet A, Brun S, Normand AC, et al. Extensive dermatophytosis caused by terbinafine-resistant Trichophyton indotineae, France. Emerg Infect Dis. 2022;28:229-233.
- Thakur S, Spruijtenburg B, Abhishek, et al. Whole genome sequence analysis of terbinafine resistant and susceptible Trichophyton isolates from human and animal origin. Mycopathologia. 2025;190:13.
- Lockhart SR, Chowdhary A, Gold JA. The rapid emergence of antifungal-resistant human-pathogenic fungi. Nat Rev Microbiol. 2023;21:818-832.
- Mosam A, Shuping L, Naicker S, et al. A case of antifungal-resistant ringworm infection in KwaZulu-Natal Province, South Africa, caused by Trichophyton indotineae. Public Health Bulletin South Africa. Accessed April 4, 2025. https://www.phbsa.ac.za/wp-content/uploads/2023/12PHBSA-Ringworm-Article-2023.pdf
- Cañete-Gibas CF, Mele J, Patterson HP, et al. Terbinafine-resistant dermatophytes and the presence of Trichophyton indotineae in North America. J Clin Microbiol. 2023;61:E0056223
- Caplan AS, Todd GC, Zhu Y, et al. Clinical course, antifungal susceptibility, and genomic sequencing of Trichophyton indotineae. JAMA Dermatol. 2024;160:701-709. doi:10.1001/jamadermatol.2024.1126
- Benedict K. Topical antifungal prescribing for Medicare Part D beneficiaries—United States, 2021. MMWR Morb Mortal Wkly Rep. 2024;73:1-5.
- Verma SB. Emergence of recalcitrant dermatophytosis in India. Lancet Infect Dis. 2018;18:718-719.
- Khurana A, Sharath S, Sardana K, et al. Clinico-mycological and therapeutic updates on cutaneous dermatophytic infections in the era of Trichophyton indotineae. J Am Acad Dermatol. 2024;91:315-323. doi:10.1016/j.jaad.2024.03.024
- Verma S. Steroid modified tinea. BMJ. 2017;356:j973.
- Khurana A, Agarwal A, Agrawal D, et al. Effect of different itraconazole dosing regimens on cure rates, treatment duration, safety, and relapse rates in adult patients with tinea corporis/cruris: a randomized clinical trial. JAMA Dermatol. 2022;158:1269-1278.
- Burmester A, Hipler UC, Uhrlaß S, et al. Indian Trichophyton mentagrophytes squalene epoxidase erg1 double mutants show high proportion of combined fluconazole and terbinafine resistance. Mycoses. 2020;63:1175-1180.
- Bhuiyan MSI, Verma SB, Illigner GM, et al. Trichophyton mentagrophytes ITS genotype VIII/Trichophyton indotineae infection and antifungal resistance in Bangladesh. J Fungi (Basel). 2024;10:768. doi:10.3390 /jof10110768
- Hay RJ. Chapter 82: superficial mycoses. In: Ryan ET, Hill DR, Solomon T, et al, eds. Hunter’s Tropical Medicine and Emerging Infectious Diseases. 10th ed. Elsevier; 2020:648-652.
- Gupta AK, Cooper EA, Wang T, et al. Detection of squalene epoxidase mutations in United States patients with onychomycosis: implications for management. J Invest Dermatol. 2023;143:2476-2483.E2477.
- Hwang JK, Bakotic WL, Gold JA, et al. Isolation of terbinafine-resistant Trichophyton rubrum from onychomycosis patients who failed treatment at an academic center in New York, United States. J Fungi. 2023;9:710.
- Gu D, Hatch M, Ghannoum M, et al. Treatment-resistant dermatophytosis: a representative case highlighting an emerging public health threat. JAAD Case Rep. 2020;6:1153-1155.
- Jabet A, Dellière S, Seang S, et al. Sexually transmitted Trichophyton mentagrophytes genotype VII infection among men who have sex with men. Emerg Infect Dis. 2023;29:1411-1414.
- Zucker J, Caplan AS, Gunaratne SH, et al. Notes from the field: Trichophyton mentagrophytes genotype VII—New York City, April-July 2024. MMWR Morb Mortal Wkly Rep. 2024;73:985-988.
- Jabet A, Bérot V, Chiarabini T, et al. Trichophyton mentagrophytes ITS genotype VII infections among men who have sex with men in France: an ongoing phenomenon. J Eur Acad Dermatol Venereol. 2025;39:407-415.
- Caplan AS, Gold JA, Smith DJ, et al. Improving antifungal stewardship in dermatology in an era of emerging dermatophyte resistance. JAAD International. 2024;15:168-169.
- Elewski B. A call for antifungal stewardship. Br J Dermatol. 2020; 183:798-799.
- Gold JAW, Benedict K, Caplan AS, et al. High rates of potentially unnecessary topical antifungal prescribing in a large commercial health insurance claims database, United States. J Am Acad Dermatol. 2025:S0190-9622(25)00098-2. doi:10.1016/j.jaad.2025.01.022
- Yadgar RJ, Bhatia N, Friedman A. Cutaneous fungal infections are commonly misdiagnosed: a survey-based study. J Am Acad Dermatol. 2017;76:562-563.
- Flint ND, Rhoads JLW, Carlisle R, et al. The continued inappropriate use and overuse of combination topical clotrimazole-betamethasone. Dermatol Online J. 2021;27. doi:10.5070/D327854686
- Currie DW, Caplan AS, Benedict K, et al. Prescribing of clotrimazolebetamethasone dipropionate, a topical combination corticosteroidantifungal product, for Medicare part D beneficiaries, United States, 2016–2022. Antimicrob Steward Healthc Epidemiol. 2024;4:E174.
- Gold JA, Caplan AS, Benedict K, et al. Clotrimazole-betamethasone dipropionate prescribing for nonfungal skin conditions. JAMA Network Open. 2024;7:E2411721-E2411721.
The Rise of Antifungal-Resistant Dermatophyte Infections: What Dermatologists Need to Know
The Rise of Antifungal-Resistant Dermatophyte Infections: What Dermatologists Need to Know
PRACTICE POINTS
- Recently emerged dermatophyte species pose a global public health concern because of infection severity, frequent resistance to terbinafine, and easy person-to-person transmission.
- Prolonged itraconazole therapy is considered the firstline treatment for infections caused by Trichophyton indotineae, a globally emerging and frequently terbinafine-resistant dermatophyte.
- Dermatologists can educate nondermatologists on the importance of mycologic confirmation and avoidance of the use of topical antifungal/ corticosteroid products, which are hypothesized to contribute to emergence and spread of resistance.
Implications of Thyroid Disease in Hospitalized Patients With Hidradenitis Suppurativa
Implications of Thyroid Disease in Hospitalized Patients With Hidradenitis Suppurativa
To the Editor:
Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition characterized by painful recurrent abscesses. Several autoimmune and endocrine diseases are associated with HS, including inflammatory bowel disease and diabetes mellitus (DM).1 Notably, the association between HS and thyroid disorders is poorly characterized,2 and there are no known nationwide studies exploring this potential association in the hospital setting. In this cross-sectional matched cohort study, we aimed to characterize HS patients with comorbid thyroid disorders as well as to explore whether thyroid disease is associated with comorbidities and hospital outcome measures in these patients.
The 2019 National Inpatient Sample (NIS) was weighted in accordance with NIS-assigned weight variables and queried for HS, hypothyroidism, and hyperthyroidism cases using International Classification of Diseases, Tenth Revision, codes L73.2, E03, and E05, respectively. Propensity score matching based on age and sex was performed using a nearest-neighbor method in the MatchIt statistical R package. Patient demographics, comorbidities, and outcome variables were collected. Univariable analysis of HS patients with thyroid disease vs those without thyroid disease vs controls without HS were performed using X2 and t-test functions in SPSS statistical software (IBM). A series of multivariate analyses were performed using SPSS logistic and linear regression models to examine the effect of thyroid disease on hospital outcome measures and comorbidities in HS patients, with statistical significance set at P=.05.
A total of 1720 HS patients with comorbid thyroid disease (hyperthyroidism/hypothyroidism), 23,785 HS patients without thyroid disease, and 25,497 age- and sex-matched controls were included in the analysis. On average, HS patients with comorbid thyroid disease were older than HS patients without thyroid disease and controls (49.36 years vs 42.17 years vs 42.66 years [P<.001]), more likely to be female (75.58% vs 58.67% vs 59.81% [P<.001]), more likely to be in the highest income quartile (17.52% vs 12.18% vs 8.14% [P<.001]), and more likely to be Medicare insured (39.07% vs 27.47% vs 18.02% [P<.001])(eTable).


On univariate analysis of hospital outcome measures, HS patients with comorbid thyroid disease had the highest frequency of extreme likelihood of dying compared with HS patients without thyroid disease and with controls (6.40% vs 5.38% vs 2.47% [P<.001]), the highest mean number of diagnoses (18.31 vs 14.14 vs 8.57 [P<.001]), and the longest mean length of hospital stay (6.03 days vs 5.94 days vs 3.73 days [P<.001]). On univariate analysis of comorbidities, HS patients with thyroid disease had the highest incidence of the following comorbidities compared with HS patients without thyroid disease and controls: hypertension (34.01% vs 28.55% vs 22.39% [P<.001]), DM (48.26% vs 35.63% vs 18.05% [P<.001]), obesity (46.80% vs 39.65% vs 11.70% [P<.001]), and acute kidney injury (AKI)(21.80% vs 13.10% vs 6.33% [P<.001])(eTable).
A multivariate analysis adjusting for multiple potential confounders including age, sex, race, median income quartile, disposition/discharge location, and primary payer was performed for hospital outcome measures and comorbidities. There were no significant differences in hospital outcome measures between HS patients with comorbid thyroid disease vs those without thyroid disease (P>.05)(Table 1). Thyroid disease was associated with increased odds of comorbid DM (odds ratio [OR], 1.242 [95% CI, 1.113-1.386]), obesity (OR, 1.173 [95% CI, 1.057-1.302]), and AKI (OR, 1.623 [95% CI, 1.423-1.851]) and decreased odds of comorbid nicotine dependence (OR, 0.609 [95% CI, 0.540-0.687]), skin and soft tissue infections (OR, 0.712 [95% CI, 0.637-0.797]), and sepsis (OR, 0.836 [95% CI, 0.717-0.973]) in HS patients (Table 2).


We found that HS patients with thyroid disease had increased odds of comorbid obesity, DM, and AKI compared with HS patients without thyroid disease when adjusting for potential confounders on multivariate analysis. A 2019 nationwide cross-sectional study of 18,224 patients with thyroid disease and 72,896 controls in Taiwan showed a higher prevalence of obesity (1.26% vs 0.57% [P<.0001]) and a higher hazard ratio (HR) of type 2 DM (HR, 1.23 [95% CI, 1.16-1.31]) in the thyroid disease group vs the controls.3 In a 2024 claims-based national cohort study of 4,152,830 patients with 2 or more consecutive thyroid-stimulating hormone measurements in the United States, patients with hypothyroidism and hyperthyroidism had a higher incidence risk for kidney dysfunction vs patients with euthyroidism (HRs, 1.37 [95% CI, 1.34–1.40] and 1.42 [95% CI, 1.39-1.45]).4 In addition, patients with and without DM and thyroid disease had increased risk for kidney disease compared to patients with and without DM and euthyroidism (hypothyroidism: HRs, 1.17 [95% CI, 1.13-1.22] and 1.52 [95% CI, 1.49-1.56]; hyperthyroidism: HRs, 1.34 [95% CI, 1.29-1.38] and 1.36 [95% CI, 1.33-1.39]). Furthermore, patients with and without obesity and thyroid disease had increased risk for kidney disease compared to patients with and without obesity and with euthyroidism (hypothyroidism: HRs, 1.40 [95% CI, 1.36-1.45] and 1.26 [95% CI, 1.21-1.32]; hyperthyroidism: HRs, 1.34 [95% CI, 1.30-1.39] and 1.35 [95% CI, 1.30-1.40]).4 However, these studies did not focus on HS patients.5
Hidradenitis suppurativa has a major comorbidity burden, including obesity, DM, and kidney disease.5 Our findings suggest a potential additive risk for these conditions in HS patients with comorbid thyroid disease; therefore, heightened surveillance for obesity, DM, and AKI in this population is encouraged. Prospective and retrospective studies in HS patients assessing the risk for each comorbidity while controlling for the others may help to better characterize these relationships.
Using multivariate analysis, we found that HS patients with comorbid thyroid disease had no significant differences in hospital outcome measures compared with HS patients without thyroid disease despite significant differences on univariate analysis (P<.05). Similarly, in a 2018 cross-sectional study of 430 HS patients and 20,780 controls in Denmark, the HS group had 10% lower thyroid-stimulating hormone levels vs the control group, but this did not significantly affect HS severity and thyroid function on multivariate analysis.6 In a 2020 cross-sectional analysis of 290 Greek HS patients, thyroid disease was associated with higher HS severity using Hurley classification (OR, 1.19 [95% CI, 1.03-1.51]) and International Hidradenitis Suppurativa Severity Score System 4 classification (OR, 1.29 [95% CI, 1.13-1.62]); however, this analysis was univariate and did not account for confounders.7 Taken together, our study and previous research suggest that thyroid disease is not an independent prognostic indicator for hospital outcome measures in HS patients when cofounders are considered and therefore may not warrant extra caution when treating hospitalized HS patients.
Nicotine dependence was an important potential confounder with regard to the effects of comorbid thyroid disease on outcomes of HS patients in our study. While we found that the prevalence of nicotine dependence was higher in HS patients vs matched controls, HS patients with comorbid thyroid disease had a lower prevalence of nicotine dependence than HS patients without thyroid disease. Furthermore, thyroid disease was associated with decreased odds of nicotine dependence in HS patients when adjusting for confounders. Previous studies have shown an association between cigarette smoking and HS. Smoking also may affect thyroid function via thiocyanate, sympathetic activation, or immunologic disturbances. Smoking may have both prothyroid and antithyroid effects.6 In a 2023 cross-sectional study of 108 HS patients and 52 age- and sex-matched controls in Germany, HS patients had higher thyroid antibody (TRAb) levels compared with controls (median TRAb level, 15.4 vs 14.2 [P=.026]), with even greater increases in TRAb in HS patients who were smokers or former smokers vs never smokers (median TRAb level, 1.18 vs 1.08 [P=.042]).2
There was a lower frequency of thyroid disease in our HS cohort compared with our matched controls cohort. While there are conflicting reports on the association between HS and thyroid disease in the literature, 2 recent meta-analyses of 5 and 6 case-control studies, respectively, found an association between HS and thyroid disease (OR, 1.36 [95% CI, 1.13-1.64] and 1.88 [95% CI, 1.25-2.81]).1,8 Notably, these studies were either claims or survey based, included outpatients, or were unspecified. One potential explanation for the difference in our findings vs those of other studies could be underdiagnosis of thyroid disease in hospitalized HS patients. We found that HS patients were most frequently Medicaid or Medicare insured compared to controls, who most frequently were privately insured. Increased availability and ease of access to outpatient medical care through private health insurance may be a possible contributor to the higher frequency of diagnosed thyroid disease in control patients in our study; therefore, awareness of potential underdiagnosis of thyroid disease in hospitalized HS patients is recommended.
Limitations of our study included those inherent to the NIS database, including potential miscoding and lack of data on pharmacologic treatments. Outcome measures assessed were limited by inclusion of both primary and secondary diagnoses of HS and thyroid disease in our cohort and may have been affected by other conditions. As with any observational study, there was a possibility of unidentified confounders unaccounted for in our study.
In conclusion, in this national inpatient-matched cohort study, thyroid disease was associated with increased odds of obesity, DM, and AKI in HS inpatients but was not an independent risk factor for worse hospital outcome measures. Therefore, while increased surveillance of associated comorbidities is appropriate, thyroid disease may not be a cause for increased concern for dermatologists treating hospitalized HS patients. Prospective studies are necessary to better characterize these findings.
- Phan K, Huo YR, Charlton O, et al. Hidradenitis suppurativa and thyroid disease: systematic review and meta-analysis. J Cutan Med Surg. 2020;24:23-27. doi:10.1177/1203475419874411
- Abu Rached N, Dietrich JW, Ocker L, et al. Primary thyroid dysfunction is prevalent in hidradenitis suppurativa and marked by a signature of hypothyroid Graves’ disease: a case-control study. J Clin Med. 2023;12:7490. doi:10.3390/jcm12237490
- Chen RH, Chen HY, Man KM, et al. Thyroid diseases increased the risk of type 2 diabetes mellitus: a nation-wide cohort study. Medicine (Baltimore). 2019;98:E15631. doi:10.1097/md.0000000000015631
- You AS, Kalantar-Zadeh K, Brent GA, et al. Impact of thyroid status on incident kidney dysfunction and chronic kidney disease progression in a nationally representative cohort. Mayo Clin Proc. 2024;99:39-56. doi:10.1016/j.mayocp.2023.08.028
- Almuhanna N, Tobe SW, Alhusayen R. Risk of chronic kidney disease in hospitalized patients with hidradenitis suppurativa. Dermatology. 2023;239:912-918. doi:10.1159/000531960
- Miller IM, Vinding G, Sorensen HA, et al. Thyroid function in hidradenitis suppurativa: a population]based cross]sectional study from Denmark. Clin Exp Dermatol. 2018;43:899-905. doi:10.1111/ced.13606
- Liakou AI, Kontochristopoulos G, Marnelakis I, et al. Thyroid disease and active smoking may be associated with more severe hidradenitis suppurativa: data from a prospective cross sectional single-center study. Dermatology. 2021;237:125-130. doi:10.1159/000508528
- Acharya P, Mathur M. Thyroid disorders in patients with hidradenitis suppurativa: a systematic review and meta-analysis. J Am Acad Dermatol. 2020;82:491-493. doi:10.1016/j.jaad.2019.07.025
To the Editor:
Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition characterized by painful recurrent abscesses. Several autoimmune and endocrine diseases are associated with HS, including inflammatory bowel disease and diabetes mellitus (DM).1 Notably, the association between HS and thyroid disorders is poorly characterized,2 and there are no known nationwide studies exploring this potential association in the hospital setting. In this cross-sectional matched cohort study, we aimed to characterize HS patients with comorbid thyroid disorders as well as to explore whether thyroid disease is associated with comorbidities and hospital outcome measures in these patients.
The 2019 National Inpatient Sample (NIS) was weighted in accordance with NIS-assigned weight variables and queried for HS, hypothyroidism, and hyperthyroidism cases using International Classification of Diseases, Tenth Revision, codes L73.2, E03, and E05, respectively. Propensity score matching based on age and sex was performed using a nearest-neighbor method in the MatchIt statistical R package. Patient demographics, comorbidities, and outcome variables were collected. Univariable analysis of HS patients with thyroid disease vs those without thyroid disease vs controls without HS were performed using X2 and t-test functions in SPSS statistical software (IBM). A series of multivariate analyses were performed using SPSS logistic and linear regression models to examine the effect of thyroid disease on hospital outcome measures and comorbidities in HS patients, with statistical significance set at P=.05.
A total of 1720 HS patients with comorbid thyroid disease (hyperthyroidism/hypothyroidism), 23,785 HS patients without thyroid disease, and 25,497 age- and sex-matched controls were included in the analysis. On average, HS patients with comorbid thyroid disease were older than HS patients without thyroid disease and controls (49.36 years vs 42.17 years vs 42.66 years [P<.001]), more likely to be female (75.58% vs 58.67% vs 59.81% [P<.001]), more likely to be in the highest income quartile (17.52% vs 12.18% vs 8.14% [P<.001]), and more likely to be Medicare insured (39.07% vs 27.47% vs 18.02% [P<.001])(eTable).


On univariate analysis of hospital outcome measures, HS patients with comorbid thyroid disease had the highest frequency of extreme likelihood of dying compared with HS patients without thyroid disease and with controls (6.40% vs 5.38% vs 2.47% [P<.001]), the highest mean number of diagnoses (18.31 vs 14.14 vs 8.57 [P<.001]), and the longest mean length of hospital stay (6.03 days vs 5.94 days vs 3.73 days [P<.001]). On univariate analysis of comorbidities, HS patients with thyroid disease had the highest incidence of the following comorbidities compared with HS patients without thyroid disease and controls: hypertension (34.01% vs 28.55% vs 22.39% [P<.001]), DM (48.26% vs 35.63% vs 18.05% [P<.001]), obesity (46.80% vs 39.65% vs 11.70% [P<.001]), and acute kidney injury (AKI)(21.80% vs 13.10% vs 6.33% [P<.001])(eTable).
A multivariate analysis adjusting for multiple potential confounders including age, sex, race, median income quartile, disposition/discharge location, and primary payer was performed for hospital outcome measures and comorbidities. There were no significant differences in hospital outcome measures between HS patients with comorbid thyroid disease vs those without thyroid disease (P>.05)(Table 1). Thyroid disease was associated with increased odds of comorbid DM (odds ratio [OR], 1.242 [95% CI, 1.113-1.386]), obesity (OR, 1.173 [95% CI, 1.057-1.302]), and AKI (OR, 1.623 [95% CI, 1.423-1.851]) and decreased odds of comorbid nicotine dependence (OR, 0.609 [95% CI, 0.540-0.687]), skin and soft tissue infections (OR, 0.712 [95% CI, 0.637-0.797]), and sepsis (OR, 0.836 [95% CI, 0.717-0.973]) in HS patients (Table 2).


We found that HS patients with thyroid disease had increased odds of comorbid obesity, DM, and AKI compared with HS patients without thyroid disease when adjusting for potential confounders on multivariate analysis. A 2019 nationwide cross-sectional study of 18,224 patients with thyroid disease and 72,896 controls in Taiwan showed a higher prevalence of obesity (1.26% vs 0.57% [P<.0001]) and a higher hazard ratio (HR) of type 2 DM (HR, 1.23 [95% CI, 1.16-1.31]) in the thyroid disease group vs the controls.3 In a 2024 claims-based national cohort study of 4,152,830 patients with 2 or more consecutive thyroid-stimulating hormone measurements in the United States, patients with hypothyroidism and hyperthyroidism had a higher incidence risk for kidney dysfunction vs patients with euthyroidism (HRs, 1.37 [95% CI, 1.34–1.40] and 1.42 [95% CI, 1.39-1.45]).4 In addition, patients with and without DM and thyroid disease had increased risk for kidney disease compared to patients with and without DM and euthyroidism (hypothyroidism: HRs, 1.17 [95% CI, 1.13-1.22] and 1.52 [95% CI, 1.49-1.56]; hyperthyroidism: HRs, 1.34 [95% CI, 1.29-1.38] and 1.36 [95% CI, 1.33-1.39]). Furthermore, patients with and without obesity and thyroid disease had increased risk for kidney disease compared to patients with and without obesity and with euthyroidism (hypothyroidism: HRs, 1.40 [95% CI, 1.36-1.45] and 1.26 [95% CI, 1.21-1.32]; hyperthyroidism: HRs, 1.34 [95% CI, 1.30-1.39] and 1.35 [95% CI, 1.30-1.40]).4 However, these studies did not focus on HS patients.5
Hidradenitis suppurativa has a major comorbidity burden, including obesity, DM, and kidney disease.5 Our findings suggest a potential additive risk for these conditions in HS patients with comorbid thyroid disease; therefore, heightened surveillance for obesity, DM, and AKI in this population is encouraged. Prospective and retrospective studies in HS patients assessing the risk for each comorbidity while controlling for the others may help to better characterize these relationships.
Using multivariate analysis, we found that HS patients with comorbid thyroid disease had no significant differences in hospital outcome measures compared with HS patients without thyroid disease despite significant differences on univariate analysis (P<.05). Similarly, in a 2018 cross-sectional study of 430 HS patients and 20,780 controls in Denmark, the HS group had 10% lower thyroid-stimulating hormone levels vs the control group, but this did not significantly affect HS severity and thyroid function on multivariate analysis.6 In a 2020 cross-sectional analysis of 290 Greek HS patients, thyroid disease was associated with higher HS severity using Hurley classification (OR, 1.19 [95% CI, 1.03-1.51]) and International Hidradenitis Suppurativa Severity Score System 4 classification (OR, 1.29 [95% CI, 1.13-1.62]); however, this analysis was univariate and did not account for confounders.7 Taken together, our study and previous research suggest that thyroid disease is not an independent prognostic indicator for hospital outcome measures in HS patients when cofounders are considered and therefore may not warrant extra caution when treating hospitalized HS patients.
Nicotine dependence was an important potential confounder with regard to the effects of comorbid thyroid disease on outcomes of HS patients in our study. While we found that the prevalence of nicotine dependence was higher in HS patients vs matched controls, HS patients with comorbid thyroid disease had a lower prevalence of nicotine dependence than HS patients without thyroid disease. Furthermore, thyroid disease was associated with decreased odds of nicotine dependence in HS patients when adjusting for confounders. Previous studies have shown an association between cigarette smoking and HS. Smoking also may affect thyroid function via thiocyanate, sympathetic activation, or immunologic disturbances. Smoking may have both prothyroid and antithyroid effects.6 In a 2023 cross-sectional study of 108 HS patients and 52 age- and sex-matched controls in Germany, HS patients had higher thyroid antibody (TRAb) levels compared with controls (median TRAb level, 15.4 vs 14.2 [P=.026]), with even greater increases in TRAb in HS patients who were smokers or former smokers vs never smokers (median TRAb level, 1.18 vs 1.08 [P=.042]).2
There was a lower frequency of thyroid disease in our HS cohort compared with our matched controls cohort. While there are conflicting reports on the association between HS and thyroid disease in the literature, 2 recent meta-analyses of 5 and 6 case-control studies, respectively, found an association between HS and thyroid disease (OR, 1.36 [95% CI, 1.13-1.64] and 1.88 [95% CI, 1.25-2.81]).1,8 Notably, these studies were either claims or survey based, included outpatients, or were unspecified. One potential explanation for the difference in our findings vs those of other studies could be underdiagnosis of thyroid disease in hospitalized HS patients. We found that HS patients were most frequently Medicaid or Medicare insured compared to controls, who most frequently were privately insured. Increased availability and ease of access to outpatient medical care through private health insurance may be a possible contributor to the higher frequency of diagnosed thyroid disease in control patients in our study; therefore, awareness of potential underdiagnosis of thyroid disease in hospitalized HS patients is recommended.
Limitations of our study included those inherent to the NIS database, including potential miscoding and lack of data on pharmacologic treatments. Outcome measures assessed were limited by inclusion of both primary and secondary diagnoses of HS and thyroid disease in our cohort and may have been affected by other conditions. As with any observational study, there was a possibility of unidentified confounders unaccounted for in our study.
In conclusion, in this national inpatient-matched cohort study, thyroid disease was associated with increased odds of obesity, DM, and AKI in HS inpatients but was not an independent risk factor for worse hospital outcome measures. Therefore, while increased surveillance of associated comorbidities is appropriate, thyroid disease may not be a cause for increased concern for dermatologists treating hospitalized HS patients. Prospective studies are necessary to better characterize these findings.
To the Editor:
Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition characterized by painful recurrent abscesses. Several autoimmune and endocrine diseases are associated with HS, including inflammatory bowel disease and diabetes mellitus (DM).1 Notably, the association between HS and thyroid disorders is poorly characterized,2 and there are no known nationwide studies exploring this potential association in the hospital setting. In this cross-sectional matched cohort study, we aimed to characterize HS patients with comorbid thyroid disorders as well as to explore whether thyroid disease is associated with comorbidities and hospital outcome measures in these patients.
The 2019 National Inpatient Sample (NIS) was weighted in accordance with NIS-assigned weight variables and queried for HS, hypothyroidism, and hyperthyroidism cases using International Classification of Diseases, Tenth Revision, codes L73.2, E03, and E05, respectively. Propensity score matching based on age and sex was performed using a nearest-neighbor method in the MatchIt statistical R package. Patient demographics, comorbidities, and outcome variables were collected. Univariable analysis of HS patients with thyroid disease vs those without thyroid disease vs controls without HS were performed using X2 and t-test functions in SPSS statistical software (IBM). A series of multivariate analyses were performed using SPSS logistic and linear regression models to examine the effect of thyroid disease on hospital outcome measures and comorbidities in HS patients, with statistical significance set at P=.05.
A total of 1720 HS patients with comorbid thyroid disease (hyperthyroidism/hypothyroidism), 23,785 HS patients without thyroid disease, and 25,497 age- and sex-matched controls were included in the analysis. On average, HS patients with comorbid thyroid disease were older than HS patients without thyroid disease and controls (49.36 years vs 42.17 years vs 42.66 years [P<.001]), more likely to be female (75.58% vs 58.67% vs 59.81% [P<.001]), more likely to be in the highest income quartile (17.52% vs 12.18% vs 8.14% [P<.001]), and more likely to be Medicare insured (39.07% vs 27.47% vs 18.02% [P<.001])(eTable).


On univariate analysis of hospital outcome measures, HS patients with comorbid thyroid disease had the highest frequency of extreme likelihood of dying compared with HS patients without thyroid disease and with controls (6.40% vs 5.38% vs 2.47% [P<.001]), the highest mean number of diagnoses (18.31 vs 14.14 vs 8.57 [P<.001]), and the longest mean length of hospital stay (6.03 days vs 5.94 days vs 3.73 days [P<.001]). On univariate analysis of comorbidities, HS patients with thyroid disease had the highest incidence of the following comorbidities compared with HS patients without thyroid disease and controls: hypertension (34.01% vs 28.55% vs 22.39% [P<.001]), DM (48.26% vs 35.63% vs 18.05% [P<.001]), obesity (46.80% vs 39.65% vs 11.70% [P<.001]), and acute kidney injury (AKI)(21.80% vs 13.10% vs 6.33% [P<.001])(eTable).
A multivariate analysis adjusting for multiple potential confounders including age, sex, race, median income quartile, disposition/discharge location, and primary payer was performed for hospital outcome measures and comorbidities. There were no significant differences in hospital outcome measures between HS patients with comorbid thyroid disease vs those without thyroid disease (P>.05)(Table 1). Thyroid disease was associated with increased odds of comorbid DM (odds ratio [OR], 1.242 [95% CI, 1.113-1.386]), obesity (OR, 1.173 [95% CI, 1.057-1.302]), and AKI (OR, 1.623 [95% CI, 1.423-1.851]) and decreased odds of comorbid nicotine dependence (OR, 0.609 [95% CI, 0.540-0.687]), skin and soft tissue infections (OR, 0.712 [95% CI, 0.637-0.797]), and sepsis (OR, 0.836 [95% CI, 0.717-0.973]) in HS patients (Table 2).


We found that HS patients with thyroid disease had increased odds of comorbid obesity, DM, and AKI compared with HS patients without thyroid disease when adjusting for potential confounders on multivariate analysis. A 2019 nationwide cross-sectional study of 18,224 patients with thyroid disease and 72,896 controls in Taiwan showed a higher prevalence of obesity (1.26% vs 0.57% [P<.0001]) and a higher hazard ratio (HR) of type 2 DM (HR, 1.23 [95% CI, 1.16-1.31]) in the thyroid disease group vs the controls.3 In a 2024 claims-based national cohort study of 4,152,830 patients with 2 or more consecutive thyroid-stimulating hormone measurements in the United States, patients with hypothyroidism and hyperthyroidism had a higher incidence risk for kidney dysfunction vs patients with euthyroidism (HRs, 1.37 [95% CI, 1.34–1.40] and 1.42 [95% CI, 1.39-1.45]).4 In addition, patients with and without DM and thyroid disease had increased risk for kidney disease compared to patients with and without DM and euthyroidism (hypothyroidism: HRs, 1.17 [95% CI, 1.13-1.22] and 1.52 [95% CI, 1.49-1.56]; hyperthyroidism: HRs, 1.34 [95% CI, 1.29-1.38] and 1.36 [95% CI, 1.33-1.39]). Furthermore, patients with and without obesity and thyroid disease had increased risk for kidney disease compared to patients with and without obesity and with euthyroidism (hypothyroidism: HRs, 1.40 [95% CI, 1.36-1.45] and 1.26 [95% CI, 1.21-1.32]; hyperthyroidism: HRs, 1.34 [95% CI, 1.30-1.39] and 1.35 [95% CI, 1.30-1.40]).4 However, these studies did not focus on HS patients.5
Hidradenitis suppurativa has a major comorbidity burden, including obesity, DM, and kidney disease.5 Our findings suggest a potential additive risk for these conditions in HS patients with comorbid thyroid disease; therefore, heightened surveillance for obesity, DM, and AKI in this population is encouraged. Prospective and retrospective studies in HS patients assessing the risk for each comorbidity while controlling for the others may help to better characterize these relationships.
Using multivariate analysis, we found that HS patients with comorbid thyroid disease had no significant differences in hospital outcome measures compared with HS patients without thyroid disease despite significant differences on univariate analysis (P<.05). Similarly, in a 2018 cross-sectional study of 430 HS patients and 20,780 controls in Denmark, the HS group had 10% lower thyroid-stimulating hormone levels vs the control group, but this did not significantly affect HS severity and thyroid function on multivariate analysis.6 In a 2020 cross-sectional analysis of 290 Greek HS patients, thyroid disease was associated with higher HS severity using Hurley classification (OR, 1.19 [95% CI, 1.03-1.51]) and International Hidradenitis Suppurativa Severity Score System 4 classification (OR, 1.29 [95% CI, 1.13-1.62]); however, this analysis was univariate and did not account for confounders.7 Taken together, our study and previous research suggest that thyroid disease is not an independent prognostic indicator for hospital outcome measures in HS patients when cofounders are considered and therefore may not warrant extra caution when treating hospitalized HS patients.
Nicotine dependence was an important potential confounder with regard to the effects of comorbid thyroid disease on outcomes of HS patients in our study. While we found that the prevalence of nicotine dependence was higher in HS patients vs matched controls, HS patients with comorbid thyroid disease had a lower prevalence of nicotine dependence than HS patients without thyroid disease. Furthermore, thyroid disease was associated with decreased odds of nicotine dependence in HS patients when adjusting for confounders. Previous studies have shown an association between cigarette smoking and HS. Smoking also may affect thyroid function via thiocyanate, sympathetic activation, or immunologic disturbances. Smoking may have both prothyroid and antithyroid effects.6 In a 2023 cross-sectional study of 108 HS patients and 52 age- and sex-matched controls in Germany, HS patients had higher thyroid antibody (TRAb) levels compared with controls (median TRAb level, 15.4 vs 14.2 [P=.026]), with even greater increases in TRAb in HS patients who were smokers or former smokers vs never smokers (median TRAb level, 1.18 vs 1.08 [P=.042]).2
There was a lower frequency of thyroid disease in our HS cohort compared with our matched controls cohort. While there are conflicting reports on the association between HS and thyroid disease in the literature, 2 recent meta-analyses of 5 and 6 case-control studies, respectively, found an association between HS and thyroid disease (OR, 1.36 [95% CI, 1.13-1.64] and 1.88 [95% CI, 1.25-2.81]).1,8 Notably, these studies were either claims or survey based, included outpatients, or were unspecified. One potential explanation for the difference in our findings vs those of other studies could be underdiagnosis of thyroid disease in hospitalized HS patients. We found that HS patients were most frequently Medicaid or Medicare insured compared to controls, who most frequently were privately insured. Increased availability and ease of access to outpatient medical care through private health insurance may be a possible contributor to the higher frequency of diagnosed thyroid disease in control patients in our study; therefore, awareness of potential underdiagnosis of thyroid disease in hospitalized HS patients is recommended.
Limitations of our study included those inherent to the NIS database, including potential miscoding and lack of data on pharmacologic treatments. Outcome measures assessed were limited by inclusion of both primary and secondary diagnoses of HS and thyroid disease in our cohort and may have been affected by other conditions. As with any observational study, there was a possibility of unidentified confounders unaccounted for in our study.
In conclusion, in this national inpatient-matched cohort study, thyroid disease was associated with increased odds of obesity, DM, and AKI in HS inpatients but was not an independent risk factor for worse hospital outcome measures. Therefore, while increased surveillance of associated comorbidities is appropriate, thyroid disease may not be a cause for increased concern for dermatologists treating hospitalized HS patients. Prospective studies are necessary to better characterize these findings.
- Phan K, Huo YR, Charlton O, et al. Hidradenitis suppurativa and thyroid disease: systematic review and meta-analysis. J Cutan Med Surg. 2020;24:23-27. doi:10.1177/1203475419874411
- Abu Rached N, Dietrich JW, Ocker L, et al. Primary thyroid dysfunction is prevalent in hidradenitis suppurativa and marked by a signature of hypothyroid Graves’ disease: a case-control study. J Clin Med. 2023;12:7490. doi:10.3390/jcm12237490
- Chen RH, Chen HY, Man KM, et al. Thyroid diseases increased the risk of type 2 diabetes mellitus: a nation-wide cohort study. Medicine (Baltimore). 2019;98:E15631. doi:10.1097/md.0000000000015631
- You AS, Kalantar-Zadeh K, Brent GA, et al. Impact of thyroid status on incident kidney dysfunction and chronic kidney disease progression in a nationally representative cohort. Mayo Clin Proc. 2024;99:39-56. doi:10.1016/j.mayocp.2023.08.028
- Almuhanna N, Tobe SW, Alhusayen R. Risk of chronic kidney disease in hospitalized patients with hidradenitis suppurativa. Dermatology. 2023;239:912-918. doi:10.1159/000531960
- Miller IM, Vinding G, Sorensen HA, et al. Thyroid function in hidradenitis suppurativa: a population]based cross]sectional study from Denmark. Clin Exp Dermatol. 2018;43:899-905. doi:10.1111/ced.13606
- Liakou AI, Kontochristopoulos G, Marnelakis I, et al. Thyroid disease and active smoking may be associated with more severe hidradenitis suppurativa: data from a prospective cross sectional single-center study. Dermatology. 2021;237:125-130. doi:10.1159/000508528
- Acharya P, Mathur M. Thyroid disorders in patients with hidradenitis suppurativa: a systematic review and meta-analysis. J Am Acad Dermatol. 2020;82:491-493. doi:10.1016/j.jaad.2019.07.025
- Phan K, Huo YR, Charlton O, et al. Hidradenitis suppurativa and thyroid disease: systematic review and meta-analysis. J Cutan Med Surg. 2020;24:23-27. doi:10.1177/1203475419874411
- Abu Rached N, Dietrich JW, Ocker L, et al. Primary thyroid dysfunction is prevalent in hidradenitis suppurativa and marked by a signature of hypothyroid Graves’ disease: a case-control study. J Clin Med. 2023;12:7490. doi:10.3390/jcm12237490
- Chen RH, Chen HY, Man KM, et al. Thyroid diseases increased the risk of type 2 diabetes mellitus: a nation-wide cohort study. Medicine (Baltimore). 2019;98:E15631. doi:10.1097/md.0000000000015631
- You AS, Kalantar-Zadeh K, Brent GA, et al. Impact of thyroid status on incident kidney dysfunction and chronic kidney disease progression in a nationally representative cohort. Mayo Clin Proc. 2024;99:39-56. doi:10.1016/j.mayocp.2023.08.028
- Almuhanna N, Tobe SW, Alhusayen R. Risk of chronic kidney disease in hospitalized patients with hidradenitis suppurativa. Dermatology. 2023;239:912-918. doi:10.1159/000531960
- Miller IM, Vinding G, Sorensen HA, et al. Thyroid function in hidradenitis suppurativa: a population]based cross]sectional study from Denmark. Clin Exp Dermatol. 2018;43:899-905. doi:10.1111/ced.13606
- Liakou AI, Kontochristopoulos G, Marnelakis I, et al. Thyroid disease and active smoking may be associated with more severe hidradenitis suppurativa: data from a prospective cross sectional single-center study. Dermatology. 2021;237:125-130. doi:10.1159/000508528
- Acharya P, Mathur M. Thyroid disorders in patients with hidradenitis suppurativa: a systematic review and meta-analysis. J Am Acad Dermatol. 2020;82:491-493. doi:10.1016/j.jaad.2019.07.025
Implications of Thyroid Disease in Hospitalized Patients With Hidradenitis Suppurativa
Implications of Thyroid Disease in Hospitalized Patients With Hidradenitis Suppurativa
PRACTICE
- Hidradenitis suppurativa (HS) is associated with autoimmune and endocrine conditions, but the association between HS and thyroid disorders is poorly characterized.
Comorbidities and Lifestyle Risk Factors Associated With Scabies Infestation
Comorbidities and Lifestyle Risk Factors Associated With Scabies Infestation
To the Editor:
Scabies infestation, which has been recognized as a neglected tropical disease by the World Health Organization since 2017, is caused by the human itch mite (Sarcoptes scabiei var hominis).1 Infected individuals experience a pruritic papular rash when the mite burrows into the epidermis, where it lives and lays eggs.2,3 Infected individuals also may develop bacterial superinfections if the skin barrier becomes compromised, leading to systemic complications and considerable morbidity.3
In countries with high human development indices, scabies outbreaks are linked to densely populated living conditions, such as those found in nursing homes or prisons.3,4 Scabies also is transmitted via sexual contact in adults. Beyond immunosuppression, little is known about other comorbid conditions or lifestyle risk factors associated with scabies infestation.2 Because scabies can mimic a range of other dermatologic conditions such as folliculitis, atopic dermatitis, and arthropod bites, misdiagnosis is common and can lead to delayed treatment and increased transmission risk.4 In this study, we sought to examine comorbid conditions and/or lifestyle risk factors associated with scabies infestation.
A matched case-control study was performed using the Registered Tier dataset of the National Institutes of Health All of Us Research Program Curated Data Repository version 7, which includes more than 400,000 unique participants aged 18 years or older from across the United States. The All of Us Research Program excludes adults who are unable to consent independently as well as incarcerated populations and children younger than 18 years. Participants diagnosed with scabies were identified using SNOMED code 62752005 and compared to a control group matched 1:4 based on age, sex, and selfidentified race. SNOMED codes also were used to identify various comorbidities and lifestyle risk factors, including depression, bipolar disorder, anxiety, schizophrenia, peripheral vascular disease (PVD), HIV, type 2 diabetes mellitus (T2DM), unsheltered status, tobacco use, difficulty with activities of daily living, insurance status, and any recent travel history. Logistic regression models were used to calculate odds ratios (ORs) and estimate effect sizes, with statistical significance set at P<.05.
We identified 691 cases of scabies infestation and 2073 controls. The average age of the patients diagnosed with scabies was 55.1 years. Seventy percent (481/691) identified as female and 32.4% (224/491) identified as Black or African American. Matched controls were similar for all analyzed demographic characteristics (P=1.0)(eTable 1). Patients diagnosed with scabies were more likely to be unsheltered (OR, 2.33 [95% CI, 1.91-2.85]), use tobacco (OR 1.77 [95% CI, 1.48-2.11]) and have a comorbid diagnosis of HIV (OR, 3.08 [95% CI, 2.03-4.66]), T2DM (OR, 2.05 [95% CI, 1.57- 2.66]) or PVD (OR, 2.06 [95% CI, 1.43-2.97]) compared with controls (P<.001). Psychiatric comorbidities were more common in the patients diagnosed with scabies, including depression (OR, 3.07 [95% CI, 2.54-3.72]), anxiety (OR, 2.48 [95% CI, 2.06-2.98]), bipolar disorder (OR, 3.08 [95% CI, 2.34-4.05]), and schizophrenia (OR, 4.68 [95% CI, 2.93-7.49])(P<.001). Difficulties with activities of daily living, including running errands alone (OR, 2.32 [95% CI, 1.43-3.76]) and concentrating (OR, 5.78; 95% CI, 3.86-8.64), were more prevalent in the scabies group compared to controls (both P<.05). In a multivariate logistic regression model including unsheltered status as a covariate, all associations remained statistically significant (P<.05)(eTable 2).


This large diverse study demonstrated an association between scabies infestation and unsheltered status. Previous studies have shown that unsheltered populations are at increased risk for many dermatologic conditions, perhaps due to decreased access to health care and social support, lack of access to hygiene facilities (eg, public showers), and increased prevalence of substance use and psychiatric disorders among this population.5 In a cross-sectional analysis of hospitalized patients, 8.6% of unsheltered patients (n=197) had an ectoparasitic disease (including scabies) compared with 1.0% of patients with stable housing (n=1018), with a 9.43-fold increased risk for ectoparasitic infestation among unsheltered patients (95% CI, 3.79-23.47; P<.001).6 Increased attention to public health initiatives among unsheltered populations— including access to hygiene facilities and increased dermatologic services—are needed, as ectoparasitic infections are both preventable and treatable, and these initiatives could reduce morbidity associated with superimposed bacterial infections for which unsheltered patients are at increased risk.6
Our results also showed that individuals diagnosed with scabies were more likely than the controls to have been diagnosed with HIV, T2DM, and PVD. Our findings are similar to those of a systematic review of immunosuppressive factors associated with crusted scabies (a severe form of scabies infestation) in which 10.2% and 15.7% of patients (n=683) had comorbid HIV and T2DM, respectively.7 A functioning cell-mediated response to scabies mite antigens limits proliferation of the human itch mite; thus, infection with HIV/AIDS, which induces the destruction of CD4+ T cells, limits the immune system’s ability to mount an effective response against these antigens. The association of scabies with T2DM likely is multifactorial; for example, chronic hyperglycemia may lead to immune system impairment, and peripheral neuropathy may reduce the itch sensation, allowing scabies mites to proliferate without removal by scratching.7 In a descriptive epidemiologic study in Japan, 11.7% of patients with scabies (N=857) had comorbid PVD.8 Peripheral vascular disease can lead to the development of ulcers, gangrene, and stasis dermatitis, all of which compromise the skin barrier and increase susceptibility to infection.9 Notably, these associations remained even when unsheltered status was considered as a confounding variable. Because individuals with HIV, T2DM, and PVD may be at higher risk for serious complications of scabies infestation (eg, secondary bacterial infections, invasive group A streptococcal infections), prompt detection and treatment of scabies are crucial in curbing morbidity in these at-risk populations.
Our study also demonstrated that psychiatric comorbidities including depression, anxiety, bipolar disorder, and schizophrenia were associated with scabies infestation, even when controlling for unsheltered status, which may have a bidirectional relationship with mental health disorders.10 In a cross-sectional study of 83 adult patients diagnosed with scabies, 72.2% (60/83) reported moderate to extremely large effect of scabies infestation on quality of life using the Dermatology Life Quality Index, and these scores positively correlated with increased Beck Depression Scale and Beck Anxiety Scale scores (rs=0.448 and rs=0.456 0.456, respectively; both P=.000). The results of this study suggest that scabies negatively impacts quality of life, which might increase symptoms of depression and anxiety.11
Studies are needed to assess whether patients with pre-existing depression and anxiety face increased risk for scabies infestation. In a retrospective case-control study using data from the National Health Insurance Research Database of Taiwan, 0.8% (58/7096) of patients with scabies (n=7096) and 0.4% of controls (n=28,375) were newly diagnosed with bipolar disorder over a 7-year period, indicating a 1.55-fold increased risk for bipolar disorder in patients with scabies compared to those without (95% CI, 1.12-2.09; P<.05).12 Future studies are needed to determine whether the relationship between bipolar disorder and scabies is bidirectional, with pre-existing bipolar disorder evaluated as a risk factor for subsequent scabies infestation. Increased difficulties with activities of daily living, including running errands independently and concentrating, were associated with scabies. These difficulties may reflect sequelae of psychiatric illness or pruritus associated with scabies affecting daily living.
Physician awareness of comorbidities and lifestyle risk factors associated with scabies infestation may improve diagnosis and prevent treatment delays. In a retrospective study at a single dermatology outpatient clinic, 45.3% of patients with scabies (n=428) had previously been misdiagnosed with another dermatologic condition, and the most common erroneous diagnosis was atopic dermatitis.13 Our study provides a framework of comorbidities and lifestyle risk factors associated with scabies infestation that dermatologists can use to stratify patients who may be at greater risk for this condition, allowing dermatologists to select appropriate treatment when clinical signs are ambiguous.
Limitations of our study included the potential for miscoding in the database, lack of information about treatment regimens employed (if any), and lack of information about the temporal relationship between associations.
In summary, it is recommended that patients with pruritus and other characteristic clinical findings of scabies receive appropriate workup for scabies regardless of risk factors; however, the medical and psychiatric comorbidities and lifestyle risk factors identified in this study may help to identify at-risk patients. Our study showed that unsheltered patients are at increased risk for scabies, potentially due to unique dermatologic challenges and lack of access to health care and hygiene facilities. Positive correlations between scabies and HIV, T2DM, and PVD suggest that patients with chronic immunocompromising illnesses who live in group homes or other crowded quarters and present with symptoms could be evaluated for scabies infestation to prevent widespread and difficult- to-control outbreaks in these communities. Based on our findings, scabies also should be included in the differential diagnosis for patients with psychiatric illness and suggestive symptoms. Early identification and treatment of scabies infestation could prevent misdiagnosis and treatment delays.
- World Health Organization. Scabies fact sheet. May 31, 2023. Accessed February 13, 2025. https://www.who.int/news-room/fact-sheets/detail/scabies
- Chandler DJ, Fuller LC. A review of scabies: an infestation more than skin deep. Dermatology. 2019;235:79-90. doi:10.1159/000495290
- Schneider S, Wu J, Tizek L, et al. Prevalence of scabies worldwidean updated systematic literature review in 2022. J Eur Acad Dermatol Venereol. 2023;37:1749-1757. doi:10.1111/jdv.19167
- Thomas C, Coates SJ, Engelman D, et al. Ectoparasites: Scabies. J Am Acad Dermatol. 2020;82:533-548. doi:10.1016/j.jaad.2019.05.109
- Henry T, Khachemoune A. Dermatologic conditions and risk factors in people experiencing homelessness (PEH): systematic review. Arch Dermatol Res. 2023;315:2795-2803. doi:10.1007/s00403-023-02722-2
- Zakaria A, Amerson EH, Kim-Lim P, et al. Characterization of dermatological diagnoses among hospitalized patients experiencing homelessness. Clin Exp Dermatol. 2022;47:117-120. doi:10.1111/ced.14828
- Bergamin G, Hudson J, Currie BJ, et al. A systematic review of immunosuppressive risk factors and comorbidities associated with the development of crusted scabies. Int J Infect Dis. 2024;143:107036. doi:10.1016/j.ijid.2024.107036
- Yamaguchi Y, Murata F, Maeda M, et al. Investigating the epidemiology and outbreaks of scabies in Japanese households, residential care facilities, and hospitals using claims data: the Longevity Improvement & Fair Evidence (LIFE) study. IJID Reg. 2024;11:100353. doi:10.1016 /j.ijregi.2024.03.008
- Raja A, Karch J, Shih AF, et al. Part II: Cutaneous manifestations of peripheral vascular disease. J Am Acad Dermatol. 2023;89:211-226. doi:10.1016/j.jaad.2021.05.077
- Barry R, Anderson J, Tran L, et al. Prevalence of mental health disorders among individuals experiencing homelessness: a systematic review and meta-analysis. JAMA Psychiatry. 2024;81:691-699. doi:10.1001 /jamapsychiatry.2024.0426
- Koc Y.ld.r.m S, Demirel Og. ut N, Erbag. c. E, et al. Scabies affects quality of life in correlation with depression and anxiety. Dermatol Pract Concept. 2023;13:E2023144. doi:10.5826/dpc.1302a144
- Lin CY, Chang FW, Yang JJ, et al. Increased risk of bipolar disorder in patients with scabies: a nationwide population-based matched-cohort study. Psychiatry Res. 2017;257:14-20. doi:10.1016 /j.psychres.2017.07.013
- Anderson KL, Strowd LC. Epidemiology, diagnosis, and treatment of scabies in a dermatology office. J Am Board Fam Med. 2017;30:78-84. doi:10.3122/jabfm.2017.01.160190
To the Editor:
Scabies infestation, which has been recognized as a neglected tropical disease by the World Health Organization since 2017, is caused by the human itch mite (Sarcoptes scabiei var hominis).1 Infected individuals experience a pruritic papular rash when the mite burrows into the epidermis, where it lives and lays eggs.2,3 Infected individuals also may develop bacterial superinfections if the skin barrier becomes compromised, leading to systemic complications and considerable morbidity.3
In countries with high human development indices, scabies outbreaks are linked to densely populated living conditions, such as those found in nursing homes or prisons.3,4 Scabies also is transmitted via sexual contact in adults. Beyond immunosuppression, little is known about other comorbid conditions or lifestyle risk factors associated with scabies infestation.2 Because scabies can mimic a range of other dermatologic conditions such as folliculitis, atopic dermatitis, and arthropod bites, misdiagnosis is common and can lead to delayed treatment and increased transmission risk.4 In this study, we sought to examine comorbid conditions and/or lifestyle risk factors associated with scabies infestation.
A matched case-control study was performed using the Registered Tier dataset of the National Institutes of Health All of Us Research Program Curated Data Repository version 7, which includes more than 400,000 unique participants aged 18 years or older from across the United States. The All of Us Research Program excludes adults who are unable to consent independently as well as incarcerated populations and children younger than 18 years. Participants diagnosed with scabies were identified using SNOMED code 62752005 and compared to a control group matched 1:4 based on age, sex, and selfidentified race. SNOMED codes also were used to identify various comorbidities and lifestyle risk factors, including depression, bipolar disorder, anxiety, schizophrenia, peripheral vascular disease (PVD), HIV, type 2 diabetes mellitus (T2DM), unsheltered status, tobacco use, difficulty with activities of daily living, insurance status, and any recent travel history. Logistic regression models were used to calculate odds ratios (ORs) and estimate effect sizes, with statistical significance set at P<.05.
We identified 691 cases of scabies infestation and 2073 controls. The average age of the patients diagnosed with scabies was 55.1 years. Seventy percent (481/691) identified as female and 32.4% (224/491) identified as Black or African American. Matched controls were similar for all analyzed demographic characteristics (P=1.0)(eTable 1). Patients diagnosed with scabies were more likely to be unsheltered (OR, 2.33 [95% CI, 1.91-2.85]), use tobacco (OR 1.77 [95% CI, 1.48-2.11]) and have a comorbid diagnosis of HIV (OR, 3.08 [95% CI, 2.03-4.66]), T2DM (OR, 2.05 [95% CI, 1.57- 2.66]) or PVD (OR, 2.06 [95% CI, 1.43-2.97]) compared with controls (P<.001). Psychiatric comorbidities were more common in the patients diagnosed with scabies, including depression (OR, 3.07 [95% CI, 2.54-3.72]), anxiety (OR, 2.48 [95% CI, 2.06-2.98]), bipolar disorder (OR, 3.08 [95% CI, 2.34-4.05]), and schizophrenia (OR, 4.68 [95% CI, 2.93-7.49])(P<.001). Difficulties with activities of daily living, including running errands alone (OR, 2.32 [95% CI, 1.43-3.76]) and concentrating (OR, 5.78; 95% CI, 3.86-8.64), were more prevalent in the scabies group compared to controls (both P<.05). In a multivariate logistic regression model including unsheltered status as a covariate, all associations remained statistically significant (P<.05)(eTable 2).


This large diverse study demonstrated an association between scabies infestation and unsheltered status. Previous studies have shown that unsheltered populations are at increased risk for many dermatologic conditions, perhaps due to decreased access to health care and social support, lack of access to hygiene facilities (eg, public showers), and increased prevalence of substance use and psychiatric disorders among this population.5 In a cross-sectional analysis of hospitalized patients, 8.6% of unsheltered patients (n=197) had an ectoparasitic disease (including scabies) compared with 1.0% of patients with stable housing (n=1018), with a 9.43-fold increased risk for ectoparasitic infestation among unsheltered patients (95% CI, 3.79-23.47; P<.001).6 Increased attention to public health initiatives among unsheltered populations— including access to hygiene facilities and increased dermatologic services—are needed, as ectoparasitic infections are both preventable and treatable, and these initiatives could reduce morbidity associated with superimposed bacterial infections for which unsheltered patients are at increased risk.6
Our results also showed that individuals diagnosed with scabies were more likely than the controls to have been diagnosed with HIV, T2DM, and PVD. Our findings are similar to those of a systematic review of immunosuppressive factors associated with crusted scabies (a severe form of scabies infestation) in which 10.2% and 15.7% of patients (n=683) had comorbid HIV and T2DM, respectively.7 A functioning cell-mediated response to scabies mite antigens limits proliferation of the human itch mite; thus, infection with HIV/AIDS, which induces the destruction of CD4+ T cells, limits the immune system’s ability to mount an effective response against these antigens. The association of scabies with T2DM likely is multifactorial; for example, chronic hyperglycemia may lead to immune system impairment, and peripheral neuropathy may reduce the itch sensation, allowing scabies mites to proliferate without removal by scratching.7 In a descriptive epidemiologic study in Japan, 11.7% of patients with scabies (N=857) had comorbid PVD.8 Peripheral vascular disease can lead to the development of ulcers, gangrene, and stasis dermatitis, all of which compromise the skin barrier and increase susceptibility to infection.9 Notably, these associations remained even when unsheltered status was considered as a confounding variable. Because individuals with HIV, T2DM, and PVD may be at higher risk for serious complications of scabies infestation (eg, secondary bacterial infections, invasive group A streptococcal infections), prompt detection and treatment of scabies are crucial in curbing morbidity in these at-risk populations.
Our study also demonstrated that psychiatric comorbidities including depression, anxiety, bipolar disorder, and schizophrenia were associated with scabies infestation, even when controlling for unsheltered status, which may have a bidirectional relationship with mental health disorders.10 In a cross-sectional study of 83 adult patients diagnosed with scabies, 72.2% (60/83) reported moderate to extremely large effect of scabies infestation on quality of life using the Dermatology Life Quality Index, and these scores positively correlated with increased Beck Depression Scale and Beck Anxiety Scale scores (rs=0.448 and rs=0.456 0.456, respectively; both P=.000). The results of this study suggest that scabies negatively impacts quality of life, which might increase symptoms of depression and anxiety.11
Studies are needed to assess whether patients with pre-existing depression and anxiety face increased risk for scabies infestation. In a retrospective case-control study using data from the National Health Insurance Research Database of Taiwan, 0.8% (58/7096) of patients with scabies (n=7096) and 0.4% of controls (n=28,375) were newly diagnosed with bipolar disorder over a 7-year period, indicating a 1.55-fold increased risk for bipolar disorder in patients with scabies compared to those without (95% CI, 1.12-2.09; P<.05).12 Future studies are needed to determine whether the relationship between bipolar disorder and scabies is bidirectional, with pre-existing bipolar disorder evaluated as a risk factor for subsequent scabies infestation. Increased difficulties with activities of daily living, including running errands independently and concentrating, were associated with scabies. These difficulties may reflect sequelae of psychiatric illness or pruritus associated with scabies affecting daily living.
Physician awareness of comorbidities and lifestyle risk factors associated with scabies infestation may improve diagnosis and prevent treatment delays. In a retrospective study at a single dermatology outpatient clinic, 45.3% of patients with scabies (n=428) had previously been misdiagnosed with another dermatologic condition, and the most common erroneous diagnosis was atopic dermatitis.13 Our study provides a framework of comorbidities and lifestyle risk factors associated with scabies infestation that dermatologists can use to stratify patients who may be at greater risk for this condition, allowing dermatologists to select appropriate treatment when clinical signs are ambiguous.
Limitations of our study included the potential for miscoding in the database, lack of information about treatment regimens employed (if any), and lack of information about the temporal relationship between associations.
In summary, it is recommended that patients with pruritus and other characteristic clinical findings of scabies receive appropriate workup for scabies regardless of risk factors; however, the medical and psychiatric comorbidities and lifestyle risk factors identified in this study may help to identify at-risk patients. Our study showed that unsheltered patients are at increased risk for scabies, potentially due to unique dermatologic challenges and lack of access to health care and hygiene facilities. Positive correlations between scabies and HIV, T2DM, and PVD suggest that patients with chronic immunocompromising illnesses who live in group homes or other crowded quarters and present with symptoms could be evaluated for scabies infestation to prevent widespread and difficult- to-control outbreaks in these communities. Based on our findings, scabies also should be included in the differential diagnosis for patients with psychiatric illness and suggestive symptoms. Early identification and treatment of scabies infestation could prevent misdiagnosis and treatment delays.
To the Editor:
Scabies infestation, which has been recognized as a neglected tropical disease by the World Health Organization since 2017, is caused by the human itch mite (Sarcoptes scabiei var hominis).1 Infected individuals experience a pruritic papular rash when the mite burrows into the epidermis, where it lives and lays eggs.2,3 Infected individuals also may develop bacterial superinfections if the skin barrier becomes compromised, leading to systemic complications and considerable morbidity.3
In countries with high human development indices, scabies outbreaks are linked to densely populated living conditions, such as those found in nursing homes or prisons.3,4 Scabies also is transmitted via sexual contact in adults. Beyond immunosuppression, little is known about other comorbid conditions or lifestyle risk factors associated with scabies infestation.2 Because scabies can mimic a range of other dermatologic conditions such as folliculitis, atopic dermatitis, and arthropod bites, misdiagnosis is common and can lead to delayed treatment and increased transmission risk.4 In this study, we sought to examine comorbid conditions and/or lifestyle risk factors associated with scabies infestation.
A matched case-control study was performed using the Registered Tier dataset of the National Institutes of Health All of Us Research Program Curated Data Repository version 7, which includes more than 400,000 unique participants aged 18 years or older from across the United States. The All of Us Research Program excludes adults who are unable to consent independently as well as incarcerated populations and children younger than 18 years. Participants diagnosed with scabies were identified using SNOMED code 62752005 and compared to a control group matched 1:4 based on age, sex, and selfidentified race. SNOMED codes also were used to identify various comorbidities and lifestyle risk factors, including depression, bipolar disorder, anxiety, schizophrenia, peripheral vascular disease (PVD), HIV, type 2 diabetes mellitus (T2DM), unsheltered status, tobacco use, difficulty with activities of daily living, insurance status, and any recent travel history. Logistic regression models were used to calculate odds ratios (ORs) and estimate effect sizes, with statistical significance set at P<.05.
We identified 691 cases of scabies infestation and 2073 controls. The average age of the patients diagnosed with scabies was 55.1 years. Seventy percent (481/691) identified as female and 32.4% (224/491) identified as Black or African American. Matched controls were similar for all analyzed demographic characteristics (P=1.0)(eTable 1). Patients diagnosed with scabies were more likely to be unsheltered (OR, 2.33 [95% CI, 1.91-2.85]), use tobacco (OR 1.77 [95% CI, 1.48-2.11]) and have a comorbid diagnosis of HIV (OR, 3.08 [95% CI, 2.03-4.66]), T2DM (OR, 2.05 [95% CI, 1.57- 2.66]) or PVD (OR, 2.06 [95% CI, 1.43-2.97]) compared with controls (P<.001). Psychiatric comorbidities were more common in the patients diagnosed with scabies, including depression (OR, 3.07 [95% CI, 2.54-3.72]), anxiety (OR, 2.48 [95% CI, 2.06-2.98]), bipolar disorder (OR, 3.08 [95% CI, 2.34-4.05]), and schizophrenia (OR, 4.68 [95% CI, 2.93-7.49])(P<.001). Difficulties with activities of daily living, including running errands alone (OR, 2.32 [95% CI, 1.43-3.76]) and concentrating (OR, 5.78; 95% CI, 3.86-8.64), were more prevalent in the scabies group compared to controls (both P<.05). In a multivariate logistic regression model including unsheltered status as a covariate, all associations remained statistically significant (P<.05)(eTable 2).


This large diverse study demonstrated an association between scabies infestation and unsheltered status. Previous studies have shown that unsheltered populations are at increased risk for many dermatologic conditions, perhaps due to decreased access to health care and social support, lack of access to hygiene facilities (eg, public showers), and increased prevalence of substance use and psychiatric disorders among this population.5 In a cross-sectional analysis of hospitalized patients, 8.6% of unsheltered patients (n=197) had an ectoparasitic disease (including scabies) compared with 1.0% of patients with stable housing (n=1018), with a 9.43-fold increased risk for ectoparasitic infestation among unsheltered patients (95% CI, 3.79-23.47; P<.001).6 Increased attention to public health initiatives among unsheltered populations— including access to hygiene facilities and increased dermatologic services—are needed, as ectoparasitic infections are both preventable and treatable, and these initiatives could reduce morbidity associated with superimposed bacterial infections for which unsheltered patients are at increased risk.6
Our results also showed that individuals diagnosed with scabies were more likely than the controls to have been diagnosed with HIV, T2DM, and PVD. Our findings are similar to those of a systematic review of immunosuppressive factors associated with crusted scabies (a severe form of scabies infestation) in which 10.2% and 15.7% of patients (n=683) had comorbid HIV and T2DM, respectively.7 A functioning cell-mediated response to scabies mite antigens limits proliferation of the human itch mite; thus, infection with HIV/AIDS, which induces the destruction of CD4+ T cells, limits the immune system’s ability to mount an effective response against these antigens. The association of scabies with T2DM likely is multifactorial; for example, chronic hyperglycemia may lead to immune system impairment, and peripheral neuropathy may reduce the itch sensation, allowing scabies mites to proliferate without removal by scratching.7 In a descriptive epidemiologic study in Japan, 11.7% of patients with scabies (N=857) had comorbid PVD.8 Peripheral vascular disease can lead to the development of ulcers, gangrene, and stasis dermatitis, all of which compromise the skin barrier and increase susceptibility to infection.9 Notably, these associations remained even when unsheltered status was considered as a confounding variable. Because individuals with HIV, T2DM, and PVD may be at higher risk for serious complications of scabies infestation (eg, secondary bacterial infections, invasive group A streptococcal infections), prompt detection and treatment of scabies are crucial in curbing morbidity in these at-risk populations.
Our study also demonstrated that psychiatric comorbidities including depression, anxiety, bipolar disorder, and schizophrenia were associated with scabies infestation, even when controlling for unsheltered status, which may have a bidirectional relationship with mental health disorders.10 In a cross-sectional study of 83 adult patients diagnosed with scabies, 72.2% (60/83) reported moderate to extremely large effect of scabies infestation on quality of life using the Dermatology Life Quality Index, and these scores positively correlated with increased Beck Depression Scale and Beck Anxiety Scale scores (rs=0.448 and rs=0.456 0.456, respectively; both P=.000). The results of this study suggest that scabies negatively impacts quality of life, which might increase symptoms of depression and anxiety.11
Studies are needed to assess whether patients with pre-existing depression and anxiety face increased risk for scabies infestation. In a retrospective case-control study using data from the National Health Insurance Research Database of Taiwan, 0.8% (58/7096) of patients with scabies (n=7096) and 0.4% of controls (n=28,375) were newly diagnosed with bipolar disorder over a 7-year period, indicating a 1.55-fold increased risk for bipolar disorder in patients with scabies compared to those without (95% CI, 1.12-2.09; P<.05).12 Future studies are needed to determine whether the relationship between bipolar disorder and scabies is bidirectional, with pre-existing bipolar disorder evaluated as a risk factor for subsequent scabies infestation. Increased difficulties with activities of daily living, including running errands independently and concentrating, were associated with scabies. These difficulties may reflect sequelae of psychiatric illness or pruritus associated with scabies affecting daily living.
Physician awareness of comorbidities and lifestyle risk factors associated with scabies infestation may improve diagnosis and prevent treatment delays. In a retrospective study at a single dermatology outpatient clinic, 45.3% of patients with scabies (n=428) had previously been misdiagnosed with another dermatologic condition, and the most common erroneous diagnosis was atopic dermatitis.13 Our study provides a framework of comorbidities and lifestyle risk factors associated with scabies infestation that dermatologists can use to stratify patients who may be at greater risk for this condition, allowing dermatologists to select appropriate treatment when clinical signs are ambiguous.
Limitations of our study included the potential for miscoding in the database, lack of information about treatment regimens employed (if any), and lack of information about the temporal relationship between associations.
In summary, it is recommended that patients with pruritus and other characteristic clinical findings of scabies receive appropriate workup for scabies regardless of risk factors; however, the medical and psychiatric comorbidities and lifestyle risk factors identified in this study may help to identify at-risk patients. Our study showed that unsheltered patients are at increased risk for scabies, potentially due to unique dermatologic challenges and lack of access to health care and hygiene facilities. Positive correlations between scabies and HIV, T2DM, and PVD suggest that patients with chronic immunocompromising illnesses who live in group homes or other crowded quarters and present with symptoms could be evaluated for scabies infestation to prevent widespread and difficult- to-control outbreaks in these communities. Based on our findings, scabies also should be included in the differential diagnosis for patients with psychiatric illness and suggestive symptoms. Early identification and treatment of scabies infestation could prevent misdiagnosis and treatment delays.
- World Health Organization. Scabies fact sheet. May 31, 2023. Accessed February 13, 2025. https://www.who.int/news-room/fact-sheets/detail/scabies
- Chandler DJ, Fuller LC. A review of scabies: an infestation more than skin deep. Dermatology. 2019;235:79-90. doi:10.1159/000495290
- Schneider S, Wu J, Tizek L, et al. Prevalence of scabies worldwidean updated systematic literature review in 2022. J Eur Acad Dermatol Venereol. 2023;37:1749-1757. doi:10.1111/jdv.19167
- Thomas C, Coates SJ, Engelman D, et al. Ectoparasites: Scabies. J Am Acad Dermatol. 2020;82:533-548. doi:10.1016/j.jaad.2019.05.109
- Henry T, Khachemoune A. Dermatologic conditions and risk factors in people experiencing homelessness (PEH): systematic review. Arch Dermatol Res. 2023;315:2795-2803. doi:10.1007/s00403-023-02722-2
- Zakaria A, Amerson EH, Kim-Lim P, et al. Characterization of dermatological diagnoses among hospitalized patients experiencing homelessness. Clin Exp Dermatol. 2022;47:117-120. doi:10.1111/ced.14828
- Bergamin G, Hudson J, Currie BJ, et al. A systematic review of immunosuppressive risk factors and comorbidities associated with the development of crusted scabies. Int J Infect Dis. 2024;143:107036. doi:10.1016/j.ijid.2024.107036
- Yamaguchi Y, Murata F, Maeda M, et al. Investigating the epidemiology and outbreaks of scabies in Japanese households, residential care facilities, and hospitals using claims data: the Longevity Improvement & Fair Evidence (LIFE) study. IJID Reg. 2024;11:100353. doi:10.1016 /j.ijregi.2024.03.008
- Raja A, Karch J, Shih AF, et al. Part II: Cutaneous manifestations of peripheral vascular disease. J Am Acad Dermatol. 2023;89:211-226. doi:10.1016/j.jaad.2021.05.077
- Barry R, Anderson J, Tran L, et al. Prevalence of mental health disorders among individuals experiencing homelessness: a systematic review and meta-analysis. JAMA Psychiatry. 2024;81:691-699. doi:10.1001 /jamapsychiatry.2024.0426
- Koc Y.ld.r.m S, Demirel Og. ut N, Erbag. c. E, et al. Scabies affects quality of life in correlation with depression and anxiety. Dermatol Pract Concept. 2023;13:E2023144. doi:10.5826/dpc.1302a144
- Lin CY, Chang FW, Yang JJ, et al. Increased risk of bipolar disorder in patients with scabies: a nationwide population-based matched-cohort study. Psychiatry Res. 2017;257:14-20. doi:10.1016 /j.psychres.2017.07.013
- Anderson KL, Strowd LC. Epidemiology, diagnosis, and treatment of scabies in a dermatology office. J Am Board Fam Med. 2017;30:78-84. doi:10.3122/jabfm.2017.01.160190
- World Health Organization. Scabies fact sheet. May 31, 2023. Accessed February 13, 2025. https://www.who.int/news-room/fact-sheets/detail/scabies
- Chandler DJ, Fuller LC. A review of scabies: an infestation more than skin deep. Dermatology. 2019;235:79-90. doi:10.1159/000495290
- Schneider S, Wu J, Tizek L, et al. Prevalence of scabies worldwidean updated systematic literature review in 2022. J Eur Acad Dermatol Venereol. 2023;37:1749-1757. doi:10.1111/jdv.19167
- Thomas C, Coates SJ, Engelman D, et al. Ectoparasites: Scabies. J Am Acad Dermatol. 2020;82:533-548. doi:10.1016/j.jaad.2019.05.109
- Henry T, Khachemoune A. Dermatologic conditions and risk factors in people experiencing homelessness (PEH): systematic review. Arch Dermatol Res. 2023;315:2795-2803. doi:10.1007/s00403-023-02722-2
- Zakaria A, Amerson EH, Kim-Lim P, et al. Characterization of dermatological diagnoses among hospitalized patients experiencing homelessness. Clin Exp Dermatol. 2022;47:117-120. doi:10.1111/ced.14828
- Bergamin G, Hudson J, Currie BJ, et al. A systematic review of immunosuppressive risk factors and comorbidities associated with the development of crusted scabies. Int J Infect Dis. 2024;143:107036. doi:10.1016/j.ijid.2024.107036
- Yamaguchi Y, Murata F, Maeda M, et al. Investigating the epidemiology and outbreaks of scabies in Japanese households, residential care facilities, and hospitals using claims data: the Longevity Improvement & Fair Evidence (LIFE) study. IJID Reg. 2024;11:100353. doi:10.1016 /j.ijregi.2024.03.008
- Raja A, Karch J, Shih AF, et al. Part II: Cutaneous manifestations of peripheral vascular disease. J Am Acad Dermatol. 2023;89:211-226. doi:10.1016/j.jaad.2021.05.077
- Barry R, Anderson J, Tran L, et al. Prevalence of mental health disorders among individuals experiencing homelessness: a systematic review and meta-analysis. JAMA Psychiatry. 2024;81:691-699. doi:10.1001 /jamapsychiatry.2024.0426
- Koc Y.ld.r.m S, Demirel Og. ut N, Erbag. c. E, et al. Scabies affects quality of life in correlation with depression and anxiety. Dermatol Pract Concept. 2023;13:E2023144. doi:10.5826/dpc.1302a144
- Lin CY, Chang FW, Yang JJ, et al. Increased risk of bipolar disorder in patients with scabies: a nationwide population-based matched-cohort study. Psychiatry Res. 2017;257:14-20. doi:10.1016 /j.psychres.2017.07.013
- Anderson KL, Strowd LC. Epidemiology, diagnosis, and treatment of scabies in a dermatology office. J Am Board Fam Med. 2017;30:78-84. doi:10.3122/jabfm.2017.01.160190
Comorbidities and Lifestyle Risk Factors Associated With Scabies Infestation
Comorbidities and Lifestyle Risk Factors Associated With Scabies Infestation
PRACTICE POINTS
- Scabies infestation is caused by the human itch mite (Sarcoptes scabiei var hominis) and can be spread via sexual contact in adults.
- Crowded living conditions are associated with scabies infestation in countries with high human development indices, such as the United States.
- Patients with certain comorbid conditions or lifestyle risk factors should be screened for scabies infestation when presenting with pruritus and other characteristic clinical findings.
Nailing the Nail Biopsy: Surgical Instruments and Their Function in Nail Biopsy Procedures
Practice Gap
The term nail biopsy (NB) may refer to a punch, excisional, shave, or longitudinal biopsy of the nail matrix and/or nail bed.1 Nail surgeries, including NBs, are performed relatively infrequently. In a study using data from the Medicare Provider Utilization and Payment Database 2012-2017, only 1.01% of Mohs surgeons and 0.28% of general dermatologists in the United States performed NBs. Thirty-one states had no dermatologist-performed NBs, while 3 states had no nail biopsies performed by any physician, podiatrist, nurse practitioner, or physician assistant, indicating that there is a shortage of dermatology clinicians performing nail surgeries.2
Dermatologists may not be performing NBs due to unfamiliarity with nail unit anatomy and lack of formal NB training during residency.3 In a survey of 240 dermatology residents in the United States, 58% reported performing fewer than 10 nail procedures during residency, with 25% observing only.4 Of those surveyed, 1% had no exposure to nail procedures during 3 years of residency. Furthermore, when asked to assess their competency in nail surgery on a scale of not competent, competent, and very competent, approximately 30% responded that they were not competent.4 Without sufficient education on procedures involving the nail unit, residents may be reluctant to incorporate nail surgery into their clinical practice.
Due to their complexity, NBs require the use of several specialized surgical instruments that are not used for other dermatologic procedures, and residents and attending physicians who have limited nail training may be unfamiliar with these tools. To address this educational gap, we sought to create a guide that details the surgical instruments used for the nail matrix tangential excision (shave) biopsy technique—the most common technique used in our nail specialty clinic. This guide is intended for educational use by dermatologists who wish to incorporate NB as part of their practice.
Tools and Technique
As a major referral center, our New York City–based nail specialty clinic performs a large volume of NBs, many of them performed for clinically concerning longitudinal melanonychias for which a nail matrix shave biopsy most often is performed. We utilize a standardized tray consisting of 12 surgical instruments that are needed to successfully perform a NB from start to finish (Figure). In addition to standard surgical tray items, such as sutures and tissue scissors, additional specialized instruments are necessary for NB procedures, including a nail elevator, an English nail splitter, and skin hook.
After the initial incisions are made at 45° angles to the proximal nail fold surrounding the longitudinal band, the nail elevator is used to separate the proximal nail plate from the underlying nail bed. The English nail splitter is used to create a transverse split separating the proximal from the distal nail plate, and the proximal nail plate then is retracted using a clamp. The skin hook is used to retract the proximal nail fold to expose the pigment in the nail matrix, which is biopsied using the #15 blade and sent for histopathology. The proximal nail fold and retracted nail plate then are put back in place, and absorbable sutures are used to repair the defect. In certain cases, a 3-mm punch biopsy may be used to sample the nail plate and/or the surrounding soft tissue.
Practice Implications
A guide to surgical tools used during NB procedures, including less commonly encountered tools such as a nail elevator and English nail splitter, helps to close the educational gap of NB procedures among dermatology trainees and attending physicians. In conjunction with practical training with cadavers and models, a guide to surgical tools can be reviewed by trainees before hands-on exposure to nail surgery in a clinical setting. By increasing awareness of the tools needed to complete the procedure from start to finish, dermatologists may feel more prepared and confident in their ability to perform NBs, ultimately allowing for more rapid diagnosis of nail malignancies.
- Grover C, Bansal S. Nail biopsy: a user’s manual. Indian Dermatol Online J. 2018;9:3-15. doi:10.4103/idoj.IDOJ_268_17
- Wang Y, Lipner SR. Retrospective analysis of nail biopsies performed using the Medicare Provider Utilization and Payment Database 2012 to 2017. Dermatol Ther. 2021;34:e14928. doi:10.1111/dth.14928
- Hare AQ, Rich P. Clinical and educational gaps in diagnosis of nail disorders. Dermatol Clin. 2016;34:269-273. doi:10.1016/j.det.2016.02.002
- Lee EH, Nehal KS, Dusza SW, et al. Procedural dermatology training during dermatology residency: a survey of third-year dermatology residents. J Am Acad Dermatol. 2011;64:475-483.e4835. doi:10.1016/j.jaad.2010.05.044
Practice Gap
The term nail biopsy (NB) may refer to a punch, excisional, shave, or longitudinal biopsy of the nail matrix and/or nail bed.1 Nail surgeries, including NBs, are performed relatively infrequently. In a study using data from the Medicare Provider Utilization and Payment Database 2012-2017, only 1.01% of Mohs surgeons and 0.28% of general dermatologists in the United States performed NBs. Thirty-one states had no dermatologist-performed NBs, while 3 states had no nail biopsies performed by any physician, podiatrist, nurse practitioner, or physician assistant, indicating that there is a shortage of dermatology clinicians performing nail surgeries.2
Dermatologists may not be performing NBs due to unfamiliarity with nail unit anatomy and lack of formal NB training during residency.3 In a survey of 240 dermatology residents in the United States, 58% reported performing fewer than 10 nail procedures during residency, with 25% observing only.4 Of those surveyed, 1% had no exposure to nail procedures during 3 years of residency. Furthermore, when asked to assess their competency in nail surgery on a scale of not competent, competent, and very competent, approximately 30% responded that they were not competent.4 Without sufficient education on procedures involving the nail unit, residents may be reluctant to incorporate nail surgery into their clinical practice.
Due to their complexity, NBs require the use of several specialized surgical instruments that are not used for other dermatologic procedures, and residents and attending physicians who have limited nail training may be unfamiliar with these tools. To address this educational gap, we sought to create a guide that details the surgical instruments used for the nail matrix tangential excision (shave) biopsy technique—the most common technique used in our nail specialty clinic. This guide is intended for educational use by dermatologists who wish to incorporate NB as part of their practice.
Tools and Technique
As a major referral center, our New York City–based nail specialty clinic performs a large volume of NBs, many of them performed for clinically concerning longitudinal melanonychias for which a nail matrix shave biopsy most often is performed. We utilize a standardized tray consisting of 12 surgical instruments that are needed to successfully perform a NB from start to finish (Figure). In addition to standard surgical tray items, such as sutures and tissue scissors, additional specialized instruments are necessary for NB procedures, including a nail elevator, an English nail splitter, and skin hook.
After the initial incisions are made at 45° angles to the proximal nail fold surrounding the longitudinal band, the nail elevator is used to separate the proximal nail plate from the underlying nail bed. The English nail splitter is used to create a transverse split separating the proximal from the distal nail plate, and the proximal nail plate then is retracted using a clamp. The skin hook is used to retract the proximal nail fold to expose the pigment in the nail matrix, which is biopsied using the #15 blade and sent for histopathology. The proximal nail fold and retracted nail plate then are put back in place, and absorbable sutures are used to repair the defect. In certain cases, a 3-mm punch biopsy may be used to sample the nail plate and/or the surrounding soft tissue.
Practice Implications
A guide to surgical tools used during NB procedures, including less commonly encountered tools such as a nail elevator and English nail splitter, helps to close the educational gap of NB procedures among dermatology trainees and attending physicians. In conjunction with practical training with cadavers and models, a guide to surgical tools can be reviewed by trainees before hands-on exposure to nail surgery in a clinical setting. By increasing awareness of the tools needed to complete the procedure from start to finish, dermatologists may feel more prepared and confident in their ability to perform NBs, ultimately allowing for more rapid diagnosis of nail malignancies.
Practice Gap
The term nail biopsy (NB) may refer to a punch, excisional, shave, or longitudinal biopsy of the nail matrix and/or nail bed.1 Nail surgeries, including NBs, are performed relatively infrequently. In a study using data from the Medicare Provider Utilization and Payment Database 2012-2017, only 1.01% of Mohs surgeons and 0.28% of general dermatologists in the United States performed NBs. Thirty-one states had no dermatologist-performed NBs, while 3 states had no nail biopsies performed by any physician, podiatrist, nurse practitioner, or physician assistant, indicating that there is a shortage of dermatology clinicians performing nail surgeries.2
Dermatologists may not be performing NBs due to unfamiliarity with nail unit anatomy and lack of formal NB training during residency.3 In a survey of 240 dermatology residents in the United States, 58% reported performing fewer than 10 nail procedures during residency, with 25% observing only.4 Of those surveyed, 1% had no exposure to nail procedures during 3 years of residency. Furthermore, when asked to assess their competency in nail surgery on a scale of not competent, competent, and very competent, approximately 30% responded that they were not competent.4 Without sufficient education on procedures involving the nail unit, residents may be reluctant to incorporate nail surgery into their clinical practice.
Due to their complexity, NBs require the use of several specialized surgical instruments that are not used for other dermatologic procedures, and residents and attending physicians who have limited nail training may be unfamiliar with these tools. To address this educational gap, we sought to create a guide that details the surgical instruments used for the nail matrix tangential excision (shave) biopsy technique—the most common technique used in our nail specialty clinic. This guide is intended for educational use by dermatologists who wish to incorporate NB as part of their practice.
Tools and Technique
As a major referral center, our New York City–based nail specialty clinic performs a large volume of NBs, many of them performed for clinically concerning longitudinal melanonychias for which a nail matrix shave biopsy most often is performed. We utilize a standardized tray consisting of 12 surgical instruments that are needed to successfully perform a NB from start to finish (Figure). In addition to standard surgical tray items, such as sutures and tissue scissors, additional specialized instruments are necessary for NB procedures, including a nail elevator, an English nail splitter, and skin hook.
After the initial incisions are made at 45° angles to the proximal nail fold surrounding the longitudinal band, the nail elevator is used to separate the proximal nail plate from the underlying nail bed. The English nail splitter is used to create a transverse split separating the proximal from the distal nail plate, and the proximal nail plate then is retracted using a clamp. The skin hook is used to retract the proximal nail fold to expose the pigment in the nail matrix, which is biopsied using the #15 blade and sent for histopathology. The proximal nail fold and retracted nail plate then are put back in place, and absorbable sutures are used to repair the defect. In certain cases, a 3-mm punch biopsy may be used to sample the nail plate and/or the surrounding soft tissue.
Practice Implications
A guide to surgical tools used during NB procedures, including less commonly encountered tools such as a nail elevator and English nail splitter, helps to close the educational gap of NB procedures among dermatology trainees and attending physicians. In conjunction with practical training with cadavers and models, a guide to surgical tools can be reviewed by trainees before hands-on exposure to nail surgery in a clinical setting. By increasing awareness of the tools needed to complete the procedure from start to finish, dermatologists may feel more prepared and confident in their ability to perform NBs, ultimately allowing for more rapid diagnosis of nail malignancies.
- Grover C, Bansal S. Nail biopsy: a user’s manual. Indian Dermatol Online J. 2018;9:3-15. doi:10.4103/idoj.IDOJ_268_17
- Wang Y, Lipner SR. Retrospective analysis of nail biopsies performed using the Medicare Provider Utilization and Payment Database 2012 to 2017. Dermatol Ther. 2021;34:e14928. doi:10.1111/dth.14928
- Hare AQ, Rich P. Clinical and educational gaps in diagnosis of nail disorders. Dermatol Clin. 2016;34:269-273. doi:10.1016/j.det.2016.02.002
- Lee EH, Nehal KS, Dusza SW, et al. Procedural dermatology training during dermatology residency: a survey of third-year dermatology residents. J Am Acad Dermatol. 2011;64:475-483.e4835. doi:10.1016/j.jaad.2010.05.044
- Grover C, Bansal S. Nail biopsy: a user’s manual. Indian Dermatol Online J. 2018;9:3-15. doi:10.4103/idoj.IDOJ_268_17
- Wang Y, Lipner SR. Retrospective analysis of nail biopsies performed using the Medicare Provider Utilization and Payment Database 2012 to 2017. Dermatol Ther. 2021;34:e14928. doi:10.1111/dth.14928
- Hare AQ, Rich P. Clinical and educational gaps in diagnosis of nail disorders. Dermatol Clin. 2016;34:269-273. doi:10.1016/j.det.2016.02.002
- Lee EH, Nehal KS, Dusza SW, et al. Procedural dermatology training during dermatology residency: a survey of third-year dermatology residents. J Am Acad Dermatol. 2011;64:475-483.e4835. doi:10.1016/j.jaad.2010.05.044
Melasma Risk Factors: A Matched Cohort Study Using Data From the All of Us Research Program
To the Editor:
Melasma (also known as chloasma) is characterized by symmetric hyperpigmented patches affecting sun-exposed areas. Women commonly develop this condition during pregnancy, suggesting a connection between melasma and increased female sex hormone levels.1 Other hypothesized risk factors include sun exposure, genetic susceptibility, estrogen and/or progesterone therapy, and thyroid abnormalities but have not been corroborated.2 Treatment options are limited because the pathogenesis is poorly understood; thus, we aimed to analyze melasma risk factors using a national database with a nested case-control approach.
We conducted a matched case-control study using the Registered Tier dataset (version 7) from the National Institute of Health’s All of Us Research Program (https://allofus.nih.gov/), which is available to authorized users through the program’s Researcher Workbench and includes more than 413,000 total participants enrolled from May 1, 2018, through July 1, 2022. Cases included patients 18 years and older with a diagnosis of melasma (International Classification of Diseases, Tenth Revision, Clinical Modification code L81.1 [Chloasma]; concept ID 4264234 [Chloasma]; and Systematized Nomenclature of Medicine [SNOMED] code 36209000 [Chloasma]), and controls without a diagnosis of melasma were matched in a 1:10 ratio based on age, sex, and self-reported race. Concept IDs and SNOMED codes were used to identify individuals in each cohort with a diagnosis of alcohol dependence (concept IDs 433753, 435243, 4218106; SNOMED codes 15167005, 66590003, 7200002), depression (concept ID 440383; SNOMED code 35489007), hypothyroidism (concept ID 140673; SNOMED code 40930008), hyperthyroidism (concept ID 4142479; SNOMED code 34486009), anxiety (concept IDs 441542, 442077, 434613; SNOMED codes 48694002, 197480006, 21897009), tobacco dependence (concept IDs 37109023, 437264, 4099811; SNOMED codes 16077091000119107, 89765005, 191887008), or obesity (concept IDs 433736 and 434005; SNOMED codes 414916001 and 238136002), or with a history of radiation therapy (concept IDs 4085340, 4311117, 4061844, 4029715; SNOMED codes 24803000, 85983004, 200861004, 108290001) or hormonal medications containing estrogen and/or progesterone, including oral medications and implants (concept IDs 21602445, 40254009, 21602514, 21603814, 19049228, 21602529, 1549080, 1551673, 1549254, 21602472, 21602446, 21602450, 21602515, 21602566, 21602473, 21602567, 21602488, 21602585, 1596779, 1586808, 21602524). In our case cohort, diagnoses and exposures to treatments were only considered for analysis if they occurred prior to melasma diagnosis.
Multivariate logistic regression was performed to calculate odds ratios and P values between melasma and each comorbidity or exposure to the treatments specified. Statistical significance was set at P<.05.
We identified 744 melasma cases (mean age, 55.20 years; 95.43% female; 12.10% Black) and 7440 controls with similar demographics (ie, age, sex, race/ethnicity) between groups (all P>.05 [Table 1]). Patients with a melasma diagnosis were more likely to have a pre-existing diagnosis of depression (OR, 1.87; 95% CI, 1.51-2.31 [P<.001]) or hypothyroidism (OR, 1.31; 95% CI, 1.04-1.65 [P<.05]), or a history of radiation therapy (OR, 19.08; 95% CI, 10.20-35.69 [P<.001]) and/or estrogen and/or progesterone therapy (OR, 2.01; 95% CI, 1.69-2.40 [P<.001]) prior to melasma diagnosis. A diagnosis of anxiety prior to melasma diagnosis trended toward an association with melasma (P=.067). Pre-existing alcohol dependence, obesity, and hyperthyroidism were not associated with melasma (P=.98, P=.28, and P=.29, respectively). A diagnosis of tobacco dependence was associated with a decreased melasma risk (OR, 0.53, 95% CI, 0.37-0.76)[P<.001])(Table 2).
Our study results suggest that pre-existing depression was a risk factor for subsequent melasma diagnosis. Depression may exacerbate stress, leading to increased activation of the hypothalamic-pituitary-adrenal axis as well as increased levels of cortisol and adrenocorticotropic hormone, which subsequently act on melanocytes to increase melanogenesis.3 A retrospective study of 254 participants, including 127 with melasma, showed that increased melasma severity was associated with higher rates of depression (P=.002)2; however, the risk for melasma following a depression diagnosis has not been reported.
Our results also showed that hypothyroidism was associated with an increased risk for melasma. On a cellular level, hypothyroidism can cause systemic inflammation, potentailly leading to increased stress and melanogenesis via activation of the hypothalamic-pituitary-adrenal axis.4 These findings are similar to a systematic review and meta-analysis reporting increased thyroid-stimulating hormone, anti–thyroid peroxidase, and antithyroglobulin antibody levels associated with increased melasma risk (mean difference between cases and controls, 0.33 [95% CI, 0.18-0.47]; pooled association, P=.020; mean difference between cases and controls, 0.28 [95% CI, 0.01-0.55], respectively).5
Patients in our cohort who had a history of radiation therapy were 19 times more likely to develop melasma, similar to findings of a survey-based study of 421 breast cancer survivors in which 336 (79.81%) reported hyperpigmentation in irradiated areas.6 Patients in our cohort who had a history of estrogen and/or progesterone therapy were 2 times more likely to develop melasma, similar to a case-control study of 207 patients with melasma and 207 controls that showed combined oral contraceptives increased risk for melasma (OR, 1.23 [95% CI, 1.08-1.41; P<.01).3
Tobacco use is not a well-known protective factor against melasma. Prior studies have indicated that tobacco smoking activates melanocytes via the Wnt/β-Catenin pathway, leading to hyperpigmentation.7 Although exposure to cigarette smoke decreases angiogenesis and would more likely lead to hyperpigmentation, nicotine exposure has been shown to increase angiogenesis, which could lead to increased blood flow and partially explain the protection against melasma demonstrated in our cohort.8 Future studies are needed to explore this relationship.
Limitations of our study include lack of information about melasma severity and information about prior melasma treatment in our cohort as well as possible misdiagnosis reported in the dataset.
Our results demonstrated that pre-existing depression and hypothyroidism as well as a history of radiation or estrogen and/or progesterone therapies are potential risk factors for melasma. Therefore, we recommend that patients with melasma be screened for depression and thyroid dysfunction, and patients undergoing radiation therapy or starting estrogen and/or progesterone therapy should be counseled on their increased risk for melasma. Future studies are needed to determine whether treatment of comorbidities such as hypothyroidism and depression improve melasma severity. The decreased risk for melasma associated with tobacco use also requires further investigation.
Acknowledgments—The All of Us Research Program is supported by the National Institutes of Health, Office of the Director: Regional Medical Centers: 1 OT2 OD026549; 1 OT2 OD026554; 1 OT2 OD026557; 1 OT2 OD026556; 1 OT2 OD026550; 1 OT2 OD 026552; 1 OT2 OD026553; 1 OT2 OD026548; 1 OT2 OD026551; 1 OT2 OD026555; IAA #: AOD 16037; Federally Qualified Health Centers: HHSN 263201600085U; Data and Research Center: 5 U2C OD023196; Biobank: 1 U24 OD023121; The Participant Center: U24 OD023176; Participant Technology Systems Center: 1 U24 OD023163; Communications and Engagement: 3 OT2 OD023205; 3 OT2 OD023206; and Community Partners: 1 OT2 OD025277; 3 OT2 OD025315; 1 OT2 OD025337; 1 OT2 OD025276.
In addition, the All of Us Research Program would not be possible without the partnership of its participants, who we gratefully acknowledge for their contributions and without whom this research would not have been possible. We also thank the All of Us Research Program for making the participant data examined in this study available to us.
- Filoni A, Mariano M, Cameli N. Melasma: how hormones can modulate skin pigmentation. J Cosmet Dermatol. 2019;18:458-463. doi:10.1111/jocd.12877
- Platsidaki E, Efstathiou V, Markantoni V, et al. Self-esteem, depression, anxiety and quality of life in patients with melasma living in a sunny mediterranean area: results from a prospective cross-sectional study. Dermatol Ther (Heidelb). 2023;13:1127-1136. doi:10.1007/s13555-023-00915-1
- Handel AC, Lima PB, Tonolli VM, et al. Risk factors for facial melasma in women: a case-control study. Br J Dermatol. 2014;171:588-594. doi:10.1111/bjd.13059
- Erge E, Kiziltunc C, Balci SB, et al. A novel inflammatory marker for the diagnosis of Hashimoto’s thyroiditis: platelet-count-to-lymphocyte-count ratio (published January 22, 2023). Diseases. 2023;11:15. doi:10.3390/diseases11010015
- Kheradmand M, Afshari M, Damiani G, et al. Melasma and thyroid disorders: a systematic review and meta-analysis. Int J Dermatol. 2019;58:1231-1238. doi:10.1111/ijd.14497
- Chu CN, Hu KC, Wu RS, et al. Radiation-irritated skin and hyperpigmentation may impact the quality of life of breast cancer patients after whole breast radiotherapy (published March 31, 2021). BMC Cancer. 2021;21:330. doi:10.1186/s12885-021-08047-5
- Nakamura M, Ueda Y, Hayashi M, et al. Tobacco smoke-induced skin pigmentation is mediated by the aryl hydrocarbon receptor. Exp Dermatol. 2013;22:556-558. doi:10.1111/exd.12170
- Ejaz S, Lim CW. Toxicological overview of cigarette smoking on angiogenesis. Environ Toxicol Pharmacol. 2005;20:335-344. doi:10.1016/j.etap.2005.03.011
To the Editor:
Melasma (also known as chloasma) is characterized by symmetric hyperpigmented patches affecting sun-exposed areas. Women commonly develop this condition during pregnancy, suggesting a connection between melasma and increased female sex hormone levels.1 Other hypothesized risk factors include sun exposure, genetic susceptibility, estrogen and/or progesterone therapy, and thyroid abnormalities but have not been corroborated.2 Treatment options are limited because the pathogenesis is poorly understood; thus, we aimed to analyze melasma risk factors using a national database with a nested case-control approach.
We conducted a matched case-control study using the Registered Tier dataset (version 7) from the National Institute of Health’s All of Us Research Program (https://allofus.nih.gov/), which is available to authorized users through the program’s Researcher Workbench and includes more than 413,000 total participants enrolled from May 1, 2018, through July 1, 2022. Cases included patients 18 years and older with a diagnosis of melasma (International Classification of Diseases, Tenth Revision, Clinical Modification code L81.1 [Chloasma]; concept ID 4264234 [Chloasma]; and Systematized Nomenclature of Medicine [SNOMED] code 36209000 [Chloasma]), and controls without a diagnosis of melasma were matched in a 1:10 ratio based on age, sex, and self-reported race. Concept IDs and SNOMED codes were used to identify individuals in each cohort with a diagnosis of alcohol dependence (concept IDs 433753, 435243, 4218106; SNOMED codes 15167005, 66590003, 7200002), depression (concept ID 440383; SNOMED code 35489007), hypothyroidism (concept ID 140673; SNOMED code 40930008), hyperthyroidism (concept ID 4142479; SNOMED code 34486009), anxiety (concept IDs 441542, 442077, 434613; SNOMED codes 48694002, 197480006, 21897009), tobacco dependence (concept IDs 37109023, 437264, 4099811; SNOMED codes 16077091000119107, 89765005, 191887008), or obesity (concept IDs 433736 and 434005; SNOMED codes 414916001 and 238136002), or with a history of radiation therapy (concept IDs 4085340, 4311117, 4061844, 4029715; SNOMED codes 24803000, 85983004, 200861004, 108290001) or hormonal medications containing estrogen and/or progesterone, including oral medications and implants (concept IDs 21602445, 40254009, 21602514, 21603814, 19049228, 21602529, 1549080, 1551673, 1549254, 21602472, 21602446, 21602450, 21602515, 21602566, 21602473, 21602567, 21602488, 21602585, 1596779, 1586808, 21602524). In our case cohort, diagnoses and exposures to treatments were only considered for analysis if they occurred prior to melasma diagnosis.
Multivariate logistic regression was performed to calculate odds ratios and P values between melasma and each comorbidity or exposure to the treatments specified. Statistical significance was set at P<.05.
We identified 744 melasma cases (mean age, 55.20 years; 95.43% female; 12.10% Black) and 7440 controls with similar demographics (ie, age, sex, race/ethnicity) between groups (all P>.05 [Table 1]). Patients with a melasma diagnosis were more likely to have a pre-existing diagnosis of depression (OR, 1.87; 95% CI, 1.51-2.31 [P<.001]) or hypothyroidism (OR, 1.31; 95% CI, 1.04-1.65 [P<.05]), or a history of radiation therapy (OR, 19.08; 95% CI, 10.20-35.69 [P<.001]) and/or estrogen and/or progesterone therapy (OR, 2.01; 95% CI, 1.69-2.40 [P<.001]) prior to melasma diagnosis. A diagnosis of anxiety prior to melasma diagnosis trended toward an association with melasma (P=.067). Pre-existing alcohol dependence, obesity, and hyperthyroidism were not associated with melasma (P=.98, P=.28, and P=.29, respectively). A diagnosis of tobacco dependence was associated with a decreased melasma risk (OR, 0.53, 95% CI, 0.37-0.76)[P<.001])(Table 2).
Our study results suggest that pre-existing depression was a risk factor for subsequent melasma diagnosis. Depression may exacerbate stress, leading to increased activation of the hypothalamic-pituitary-adrenal axis as well as increased levels of cortisol and adrenocorticotropic hormone, which subsequently act on melanocytes to increase melanogenesis.3 A retrospective study of 254 participants, including 127 with melasma, showed that increased melasma severity was associated with higher rates of depression (P=.002)2; however, the risk for melasma following a depression diagnosis has not been reported.
Our results also showed that hypothyroidism was associated with an increased risk for melasma. On a cellular level, hypothyroidism can cause systemic inflammation, potentailly leading to increased stress and melanogenesis via activation of the hypothalamic-pituitary-adrenal axis.4 These findings are similar to a systematic review and meta-analysis reporting increased thyroid-stimulating hormone, anti–thyroid peroxidase, and antithyroglobulin antibody levels associated with increased melasma risk (mean difference between cases and controls, 0.33 [95% CI, 0.18-0.47]; pooled association, P=.020; mean difference between cases and controls, 0.28 [95% CI, 0.01-0.55], respectively).5
Patients in our cohort who had a history of radiation therapy were 19 times more likely to develop melasma, similar to findings of a survey-based study of 421 breast cancer survivors in which 336 (79.81%) reported hyperpigmentation in irradiated areas.6 Patients in our cohort who had a history of estrogen and/or progesterone therapy were 2 times more likely to develop melasma, similar to a case-control study of 207 patients with melasma and 207 controls that showed combined oral contraceptives increased risk for melasma (OR, 1.23 [95% CI, 1.08-1.41; P<.01).3
Tobacco use is not a well-known protective factor against melasma. Prior studies have indicated that tobacco smoking activates melanocytes via the Wnt/β-Catenin pathway, leading to hyperpigmentation.7 Although exposure to cigarette smoke decreases angiogenesis and would more likely lead to hyperpigmentation, nicotine exposure has been shown to increase angiogenesis, which could lead to increased blood flow and partially explain the protection against melasma demonstrated in our cohort.8 Future studies are needed to explore this relationship.
Limitations of our study include lack of information about melasma severity and information about prior melasma treatment in our cohort as well as possible misdiagnosis reported in the dataset.
Our results demonstrated that pre-existing depression and hypothyroidism as well as a history of radiation or estrogen and/or progesterone therapies are potential risk factors for melasma. Therefore, we recommend that patients with melasma be screened for depression and thyroid dysfunction, and patients undergoing radiation therapy or starting estrogen and/or progesterone therapy should be counseled on their increased risk for melasma. Future studies are needed to determine whether treatment of comorbidities such as hypothyroidism and depression improve melasma severity. The decreased risk for melasma associated with tobacco use also requires further investigation.
Acknowledgments—The All of Us Research Program is supported by the National Institutes of Health, Office of the Director: Regional Medical Centers: 1 OT2 OD026549; 1 OT2 OD026554; 1 OT2 OD026557; 1 OT2 OD026556; 1 OT2 OD026550; 1 OT2 OD 026552; 1 OT2 OD026553; 1 OT2 OD026548; 1 OT2 OD026551; 1 OT2 OD026555; IAA #: AOD 16037; Federally Qualified Health Centers: HHSN 263201600085U; Data and Research Center: 5 U2C OD023196; Biobank: 1 U24 OD023121; The Participant Center: U24 OD023176; Participant Technology Systems Center: 1 U24 OD023163; Communications and Engagement: 3 OT2 OD023205; 3 OT2 OD023206; and Community Partners: 1 OT2 OD025277; 3 OT2 OD025315; 1 OT2 OD025337; 1 OT2 OD025276.
In addition, the All of Us Research Program would not be possible without the partnership of its participants, who we gratefully acknowledge for their contributions and without whom this research would not have been possible. We also thank the All of Us Research Program for making the participant data examined in this study available to us.
To the Editor:
Melasma (also known as chloasma) is characterized by symmetric hyperpigmented patches affecting sun-exposed areas. Women commonly develop this condition during pregnancy, suggesting a connection between melasma and increased female sex hormone levels.1 Other hypothesized risk factors include sun exposure, genetic susceptibility, estrogen and/or progesterone therapy, and thyroid abnormalities but have not been corroborated.2 Treatment options are limited because the pathogenesis is poorly understood; thus, we aimed to analyze melasma risk factors using a national database with a nested case-control approach.
We conducted a matched case-control study using the Registered Tier dataset (version 7) from the National Institute of Health’s All of Us Research Program (https://allofus.nih.gov/), which is available to authorized users through the program’s Researcher Workbench and includes more than 413,000 total participants enrolled from May 1, 2018, through July 1, 2022. Cases included patients 18 years and older with a diagnosis of melasma (International Classification of Diseases, Tenth Revision, Clinical Modification code L81.1 [Chloasma]; concept ID 4264234 [Chloasma]; and Systematized Nomenclature of Medicine [SNOMED] code 36209000 [Chloasma]), and controls without a diagnosis of melasma were matched in a 1:10 ratio based on age, sex, and self-reported race. Concept IDs and SNOMED codes were used to identify individuals in each cohort with a diagnosis of alcohol dependence (concept IDs 433753, 435243, 4218106; SNOMED codes 15167005, 66590003, 7200002), depression (concept ID 440383; SNOMED code 35489007), hypothyroidism (concept ID 140673; SNOMED code 40930008), hyperthyroidism (concept ID 4142479; SNOMED code 34486009), anxiety (concept IDs 441542, 442077, 434613; SNOMED codes 48694002, 197480006, 21897009), tobacco dependence (concept IDs 37109023, 437264, 4099811; SNOMED codes 16077091000119107, 89765005, 191887008), or obesity (concept IDs 433736 and 434005; SNOMED codes 414916001 and 238136002), or with a history of radiation therapy (concept IDs 4085340, 4311117, 4061844, 4029715; SNOMED codes 24803000, 85983004, 200861004, 108290001) or hormonal medications containing estrogen and/or progesterone, including oral medications and implants (concept IDs 21602445, 40254009, 21602514, 21603814, 19049228, 21602529, 1549080, 1551673, 1549254, 21602472, 21602446, 21602450, 21602515, 21602566, 21602473, 21602567, 21602488, 21602585, 1596779, 1586808, 21602524). In our case cohort, diagnoses and exposures to treatments were only considered for analysis if they occurred prior to melasma diagnosis.
Multivariate logistic regression was performed to calculate odds ratios and P values between melasma and each comorbidity or exposure to the treatments specified. Statistical significance was set at P<.05.
We identified 744 melasma cases (mean age, 55.20 years; 95.43% female; 12.10% Black) and 7440 controls with similar demographics (ie, age, sex, race/ethnicity) between groups (all P>.05 [Table 1]). Patients with a melasma diagnosis were more likely to have a pre-existing diagnosis of depression (OR, 1.87; 95% CI, 1.51-2.31 [P<.001]) or hypothyroidism (OR, 1.31; 95% CI, 1.04-1.65 [P<.05]), or a history of radiation therapy (OR, 19.08; 95% CI, 10.20-35.69 [P<.001]) and/or estrogen and/or progesterone therapy (OR, 2.01; 95% CI, 1.69-2.40 [P<.001]) prior to melasma diagnosis. A diagnosis of anxiety prior to melasma diagnosis trended toward an association with melasma (P=.067). Pre-existing alcohol dependence, obesity, and hyperthyroidism were not associated with melasma (P=.98, P=.28, and P=.29, respectively). A diagnosis of tobacco dependence was associated with a decreased melasma risk (OR, 0.53, 95% CI, 0.37-0.76)[P<.001])(Table 2).
Our study results suggest that pre-existing depression was a risk factor for subsequent melasma diagnosis. Depression may exacerbate stress, leading to increased activation of the hypothalamic-pituitary-adrenal axis as well as increased levels of cortisol and adrenocorticotropic hormone, which subsequently act on melanocytes to increase melanogenesis.3 A retrospective study of 254 participants, including 127 with melasma, showed that increased melasma severity was associated with higher rates of depression (P=.002)2; however, the risk for melasma following a depression diagnosis has not been reported.
Our results also showed that hypothyroidism was associated with an increased risk for melasma. On a cellular level, hypothyroidism can cause systemic inflammation, potentailly leading to increased stress and melanogenesis via activation of the hypothalamic-pituitary-adrenal axis.4 These findings are similar to a systematic review and meta-analysis reporting increased thyroid-stimulating hormone, anti–thyroid peroxidase, and antithyroglobulin antibody levels associated with increased melasma risk (mean difference between cases and controls, 0.33 [95% CI, 0.18-0.47]; pooled association, P=.020; mean difference between cases and controls, 0.28 [95% CI, 0.01-0.55], respectively).5
Patients in our cohort who had a history of radiation therapy were 19 times more likely to develop melasma, similar to findings of a survey-based study of 421 breast cancer survivors in which 336 (79.81%) reported hyperpigmentation in irradiated areas.6 Patients in our cohort who had a history of estrogen and/or progesterone therapy were 2 times more likely to develop melasma, similar to a case-control study of 207 patients with melasma and 207 controls that showed combined oral contraceptives increased risk for melasma (OR, 1.23 [95% CI, 1.08-1.41; P<.01).3
Tobacco use is not a well-known protective factor against melasma. Prior studies have indicated that tobacco smoking activates melanocytes via the Wnt/β-Catenin pathway, leading to hyperpigmentation.7 Although exposure to cigarette smoke decreases angiogenesis and would more likely lead to hyperpigmentation, nicotine exposure has been shown to increase angiogenesis, which could lead to increased blood flow and partially explain the protection against melasma demonstrated in our cohort.8 Future studies are needed to explore this relationship.
Limitations of our study include lack of information about melasma severity and information about prior melasma treatment in our cohort as well as possible misdiagnosis reported in the dataset.
Our results demonstrated that pre-existing depression and hypothyroidism as well as a history of radiation or estrogen and/or progesterone therapies are potential risk factors for melasma. Therefore, we recommend that patients with melasma be screened for depression and thyroid dysfunction, and patients undergoing radiation therapy or starting estrogen and/or progesterone therapy should be counseled on their increased risk for melasma. Future studies are needed to determine whether treatment of comorbidities such as hypothyroidism and depression improve melasma severity. The decreased risk for melasma associated with tobacco use also requires further investigation.
Acknowledgments—The All of Us Research Program is supported by the National Institutes of Health, Office of the Director: Regional Medical Centers: 1 OT2 OD026549; 1 OT2 OD026554; 1 OT2 OD026557; 1 OT2 OD026556; 1 OT2 OD026550; 1 OT2 OD 026552; 1 OT2 OD026553; 1 OT2 OD026548; 1 OT2 OD026551; 1 OT2 OD026555; IAA #: AOD 16037; Federally Qualified Health Centers: HHSN 263201600085U; Data and Research Center: 5 U2C OD023196; Biobank: 1 U24 OD023121; The Participant Center: U24 OD023176; Participant Technology Systems Center: 1 U24 OD023163; Communications and Engagement: 3 OT2 OD023205; 3 OT2 OD023206; and Community Partners: 1 OT2 OD025277; 3 OT2 OD025315; 1 OT2 OD025337; 1 OT2 OD025276.
In addition, the All of Us Research Program would not be possible without the partnership of its participants, who we gratefully acknowledge for their contributions and without whom this research would not have been possible. We also thank the All of Us Research Program for making the participant data examined in this study available to us.
- Filoni A, Mariano M, Cameli N. Melasma: how hormones can modulate skin pigmentation. J Cosmet Dermatol. 2019;18:458-463. doi:10.1111/jocd.12877
- Platsidaki E, Efstathiou V, Markantoni V, et al. Self-esteem, depression, anxiety and quality of life in patients with melasma living in a sunny mediterranean area: results from a prospective cross-sectional study. Dermatol Ther (Heidelb). 2023;13:1127-1136. doi:10.1007/s13555-023-00915-1
- Handel AC, Lima PB, Tonolli VM, et al. Risk factors for facial melasma in women: a case-control study. Br J Dermatol. 2014;171:588-594. doi:10.1111/bjd.13059
- Erge E, Kiziltunc C, Balci SB, et al. A novel inflammatory marker for the diagnosis of Hashimoto’s thyroiditis: platelet-count-to-lymphocyte-count ratio (published January 22, 2023). Diseases. 2023;11:15. doi:10.3390/diseases11010015
- Kheradmand M, Afshari M, Damiani G, et al. Melasma and thyroid disorders: a systematic review and meta-analysis. Int J Dermatol. 2019;58:1231-1238. doi:10.1111/ijd.14497
- Chu CN, Hu KC, Wu RS, et al. Radiation-irritated skin and hyperpigmentation may impact the quality of life of breast cancer patients after whole breast radiotherapy (published March 31, 2021). BMC Cancer. 2021;21:330. doi:10.1186/s12885-021-08047-5
- Nakamura M, Ueda Y, Hayashi M, et al. Tobacco smoke-induced skin pigmentation is mediated by the aryl hydrocarbon receptor. Exp Dermatol. 2013;22:556-558. doi:10.1111/exd.12170
- Ejaz S, Lim CW. Toxicological overview of cigarette smoking on angiogenesis. Environ Toxicol Pharmacol. 2005;20:335-344. doi:10.1016/j.etap.2005.03.011
- Filoni A, Mariano M, Cameli N. Melasma: how hormones can modulate skin pigmentation. J Cosmet Dermatol. 2019;18:458-463. doi:10.1111/jocd.12877
- Platsidaki E, Efstathiou V, Markantoni V, et al. Self-esteem, depression, anxiety and quality of life in patients with melasma living in a sunny mediterranean area: results from a prospective cross-sectional study. Dermatol Ther (Heidelb). 2023;13:1127-1136. doi:10.1007/s13555-023-00915-1
- Handel AC, Lima PB, Tonolli VM, et al. Risk factors for facial melasma in women: a case-control study. Br J Dermatol. 2014;171:588-594. doi:10.1111/bjd.13059
- Erge E, Kiziltunc C, Balci SB, et al. A novel inflammatory marker for the diagnosis of Hashimoto’s thyroiditis: platelet-count-to-lymphocyte-count ratio (published January 22, 2023). Diseases. 2023;11:15. doi:10.3390/diseases11010015
- Kheradmand M, Afshari M, Damiani G, et al. Melasma and thyroid disorders: a systematic review and meta-analysis. Int J Dermatol. 2019;58:1231-1238. doi:10.1111/ijd.14497
- Chu CN, Hu KC, Wu RS, et al. Radiation-irritated skin and hyperpigmentation may impact the quality of life of breast cancer patients after whole breast radiotherapy (published March 31, 2021). BMC Cancer. 2021;21:330. doi:10.1186/s12885-021-08047-5
- Nakamura M, Ueda Y, Hayashi M, et al. Tobacco smoke-induced skin pigmentation is mediated by the aryl hydrocarbon receptor. Exp Dermatol. 2013;22:556-558. doi:10.1111/exd.12170
- Ejaz S, Lim CW. Toxicological overview of cigarette smoking on angiogenesis. Environ Toxicol Pharmacol. 2005;20:335-344. doi:10.1016/j.etap.2005.03.011
Practice Points
- Treatment options for melasma are limited due to its poorly understood pathogenesis.
- Depression and hypothyroidism and/or history of exposure to radiation and hormonal therapies may increase melasma risk.
- We recommend that patients with melasma be screened for depression and thyroid dysfunction. Patients undergoing radiation therapy or starting estrogen and/ or progesterone therapy should be counseled on the increased risk for melasma.
Optimizing Patient Care With Teledermatology: Improving Access, Efficiency, and Satisfaction
Telemedicine interest, which was relatively quiescent prior to the COVID-19 pandemic, has surged in popularity in the past few years.1 It can now be utilized seamlessly in dermatology practices to deliver exceptional patient care while reducing costs and travel time and offering dermatologists flexibility and improved work-life balance. Teledermatology applications include synchronous, asynchronous, and hybrid platforms.2 For synchronous teledermatology, patient visits are carried out in real time with audio and video technology.3 For asynchronous teledermatology—also known as the store-and-forward model—the dermatologist receives the patient’s history and photographs and then renders an assessment and treatment plan.2 Hybrid teledermatology uses real-time audio and video conferencing for history taking, assessment and treatment plan, and patient education, with photographs sent asynchronously.3 Telemedicine may not be initially intuitive or easy to integrate into clinical practice, but with time and effort, it will complement your dermatology practice, making it run more efficiently.
Patient Satisfaction With Teledermatology
Studies generally have shown very high patient satisfaction rates and shorter wait times with teledermatology vs in-person visits; for example, in a systematic review of 15 teledermatology studies including 7781 patients, more than 80% of participants reported high satisfaction with their telemedicine visit, with up to 92% reporting that they would choose to do a televisit again.4 In a retrospective analysis of 615 Zocdoc physicians, 65% of whom were dermatologists, mean wait times were 2.4 days for virtual appointments compared with 11.7 days for in-person appointments.5 Similarly, in a retrospective single-institution study, mean wait times for televisits were 14.3 days compared with 34.7 days for in-person referrals.6
Follow-Up Visits for Nail Disorders Via Teledermatology
Teledermatology may be particularly well suited for treating patients with nail disorders. In a prospective observational study, Onyeka et al7 accessed 813 images from 63 dermatology patients via teledermatology over a 6-month period to assess distance, focus, brightness, background, and image quality; of them, 83% were rated as high quality. Notably, images of nail disorders, skin growths, or pigmentation disorders were rated as having better image quality than images of inflammatory skin conditions (odds ratio [OR], 4.2-12.9 [P<.005]).7 In a retrospective study of 107 telemedicine visits for nail disorders during the COVID-19 pandemic, patients with longitudinal melanonychia were recommended for in-person visits for physical examination and dermoscopy, as were patients with suspected onychomycosis, who required nail plate sampling for diagnostic confirmation; however, approximately half of visits did not require in-person follow-up, including those patients with confirmed onychomycosis.8 Onychomycosis patients could be examined for clinical improvement and counseled on medication compliance via telemedicine. Other patients who did not require in-person follow-ups were those with traumatic nail disorders such as subungual hematoma and retronychia as well as those with body‐focused repetitive behaviors, including habit-tic nail deformity, onychophagia, and onychotillomania.8
Patients undergoing nail biopsies to rule out malignancies or to diagnose inflammatory nail disorders also may be managed via telemedicine. Patients for whom nail biopsies are recommended often are anxious about the procedure, which may be due to portrayal of nail trauma in the media9 or lack of accurate information on nail biopsies online.10 Therefore, counseling via telemedicine about the details of the procedure in a patient-friendly way (eg, showing an animated video and narrating it11) can allay anxiety without the inconvenience, cost, and time missed from work associated with traveling to an in-person visit. In addition, postoperative counseling ideally is performed via telemedicine because complications following nail procedures are uncommon. In a retrospective study of 502 patients who underwent a nail biopsy at a single academic center, only 14 developed surgical site infections within 8 days on average (range, 5–13 days), with a higher infection risk in patients with type 2 diabetes mellitus (P<.0003).12
Advantages and Limitations
There are many benefits to incorporating telemedicine into dermatology practices, including reduced overhead costs, convenience and time saved for patients, and flexibility and improved work-life balance for dermatologists. In addition, because the number of in-person visits seen generally is fixed due to space constraints and work-hour restrictions, delegating follow-up visits to telemedicine can free up in-person slots for new patients and those needing procedures. However, there also are some inherent limitations to telemedicine: technology access, vision or hearing difficulties or low digital health literacy, or language barriers. In the prospective observational study by Onyeka et al7 analyzing 813 teledermatology images, patients aged 65 to 74 years sent in more clinically useful images (OR, 7.9) and images that were more often in focus (OR, 2.6) compared with patients older than 85 years.
Final Thoughts
Incorporation of telemedicine into dermatologic practice is a valuable tool for triaging patients with acute issues, improving patient care and health care access, making practices more efficient, and improving dermatologist flexibility and work-life balance. Further development of teledermatology to provide access to underserved populations prioritizing dermatologist reimbursement and progress on technologic innovations will make teledermatology even more useful in the coming years.
- He A, Ti Kim T, Nguyen KD. Utilization of teledermatology services for dermatological diagnoses during the COVID-19 pandemic. Arch Dermatol Res. 2023;315:1059-1062.
- Lee JJ, English JC 3rd. Teledermatology: a review and update. Am J Clin Dermatol. 2018;19:253-260.
- Wang RH, Barbieri JS, Kovarik CL, et al. Synchronous and asynchronous teledermatology: a narrative review of strengths and limitations. J Telemed Telecare. 2022;28:533-538.
- Miller J, Jones E. Shaping the future of teledermatology: a literature review of patient and provider satisfaction with synchronous teledermatology during the COVID-19 pandemic. Clin Exp Dermatol. 2022;47:1903-1909.
- Gu L, Xiang L, Lipner SR. Analysis of availability of online dermatology appointments during the COVID-19 pandemic. J Am Acad Dermatol. 2021;84:517-520.
- Wang RF, Trinidad J, Lawrence J, et al. Improved patient access and outcomes with the integration of an eConsult program (teledermatology) within a large academic medical center. J Am Acad Dermatol. 2019;83:1633-1638.
- Onyeka S, Kim J, Eid E, et al. Quality of images submitted by older patients to a teledermatology platform. Abstract presented at the Society of Investigative Dermatology Annual Meeting; May 15-18, 2024; Dallas, TX.
- Chang MJ, Stewart CR, Lipner SR. Retrospective study of nail telemedicine visits during the COVID-19 pandemic. Dermatol Ther. 2021;34:E14630.
- Albucker SJ, Falotico JM, Lipner SR. A real nail biter: a cross-sectional study of 75 nail trauma scenes in international films and television series. J Cutan Med Surg. 2023;27:288-291.
- Ishack S, Lipner SR. Evaluating the impact and educational value of YouTube videos on nail biopsy procedures. Cutis. 2020;105:148-149, E1.
- Hill RC, Ho B, Lipner SR. Assuaging patient anxiety about nail biopsies with an animated educational video. J Am Acad Dermatol. Published online March 29, 2024. doi:10.1016/j.jaad.2024.03.031.
- Axler E, Lu A, Darrell M, et al. Surgical site infections are uncommon following nail biopsies in a single-center case-control study of 502 patients. J Am Acad Dermatol. Published online May 15, 2024. doi:10.1016/j.jaad.2024.05.017
Telemedicine interest, which was relatively quiescent prior to the COVID-19 pandemic, has surged in popularity in the past few years.1 It can now be utilized seamlessly in dermatology practices to deliver exceptional patient care while reducing costs and travel time and offering dermatologists flexibility and improved work-life balance. Teledermatology applications include synchronous, asynchronous, and hybrid platforms.2 For synchronous teledermatology, patient visits are carried out in real time with audio and video technology.3 For asynchronous teledermatology—also known as the store-and-forward model—the dermatologist receives the patient’s history and photographs and then renders an assessment and treatment plan.2 Hybrid teledermatology uses real-time audio and video conferencing for history taking, assessment and treatment plan, and patient education, with photographs sent asynchronously.3 Telemedicine may not be initially intuitive or easy to integrate into clinical practice, but with time and effort, it will complement your dermatology practice, making it run more efficiently.
Patient Satisfaction With Teledermatology
Studies generally have shown very high patient satisfaction rates and shorter wait times with teledermatology vs in-person visits; for example, in a systematic review of 15 teledermatology studies including 7781 patients, more than 80% of participants reported high satisfaction with their telemedicine visit, with up to 92% reporting that they would choose to do a televisit again.4 In a retrospective analysis of 615 Zocdoc physicians, 65% of whom were dermatologists, mean wait times were 2.4 days for virtual appointments compared with 11.7 days for in-person appointments.5 Similarly, in a retrospective single-institution study, mean wait times for televisits were 14.3 days compared with 34.7 days for in-person referrals.6
Follow-Up Visits for Nail Disorders Via Teledermatology
Teledermatology may be particularly well suited for treating patients with nail disorders. In a prospective observational study, Onyeka et al7 accessed 813 images from 63 dermatology patients via teledermatology over a 6-month period to assess distance, focus, brightness, background, and image quality; of them, 83% were rated as high quality. Notably, images of nail disorders, skin growths, or pigmentation disorders were rated as having better image quality than images of inflammatory skin conditions (odds ratio [OR], 4.2-12.9 [P<.005]).7 In a retrospective study of 107 telemedicine visits for nail disorders during the COVID-19 pandemic, patients with longitudinal melanonychia were recommended for in-person visits for physical examination and dermoscopy, as were patients with suspected onychomycosis, who required nail plate sampling for diagnostic confirmation; however, approximately half of visits did not require in-person follow-up, including those patients with confirmed onychomycosis.8 Onychomycosis patients could be examined for clinical improvement and counseled on medication compliance via telemedicine. Other patients who did not require in-person follow-ups were those with traumatic nail disorders such as subungual hematoma and retronychia as well as those with body‐focused repetitive behaviors, including habit-tic nail deformity, onychophagia, and onychotillomania.8
Patients undergoing nail biopsies to rule out malignancies or to diagnose inflammatory nail disorders also may be managed via telemedicine. Patients for whom nail biopsies are recommended often are anxious about the procedure, which may be due to portrayal of nail trauma in the media9 or lack of accurate information on nail biopsies online.10 Therefore, counseling via telemedicine about the details of the procedure in a patient-friendly way (eg, showing an animated video and narrating it11) can allay anxiety without the inconvenience, cost, and time missed from work associated with traveling to an in-person visit. In addition, postoperative counseling ideally is performed via telemedicine because complications following nail procedures are uncommon. In a retrospective study of 502 patients who underwent a nail biopsy at a single academic center, only 14 developed surgical site infections within 8 days on average (range, 5–13 days), with a higher infection risk in patients with type 2 diabetes mellitus (P<.0003).12
Advantages and Limitations
There are many benefits to incorporating telemedicine into dermatology practices, including reduced overhead costs, convenience and time saved for patients, and flexibility and improved work-life balance for dermatologists. In addition, because the number of in-person visits seen generally is fixed due to space constraints and work-hour restrictions, delegating follow-up visits to telemedicine can free up in-person slots for new patients and those needing procedures. However, there also are some inherent limitations to telemedicine: technology access, vision or hearing difficulties or low digital health literacy, or language barriers. In the prospective observational study by Onyeka et al7 analyzing 813 teledermatology images, patients aged 65 to 74 years sent in more clinically useful images (OR, 7.9) and images that were more often in focus (OR, 2.6) compared with patients older than 85 years.
Final Thoughts
Incorporation of telemedicine into dermatologic practice is a valuable tool for triaging patients with acute issues, improving patient care and health care access, making practices more efficient, and improving dermatologist flexibility and work-life balance. Further development of teledermatology to provide access to underserved populations prioritizing dermatologist reimbursement and progress on technologic innovations will make teledermatology even more useful in the coming years.
Telemedicine interest, which was relatively quiescent prior to the COVID-19 pandemic, has surged in popularity in the past few years.1 It can now be utilized seamlessly in dermatology practices to deliver exceptional patient care while reducing costs and travel time and offering dermatologists flexibility and improved work-life balance. Teledermatology applications include synchronous, asynchronous, and hybrid platforms.2 For synchronous teledermatology, patient visits are carried out in real time with audio and video technology.3 For asynchronous teledermatology—also known as the store-and-forward model—the dermatologist receives the patient’s history and photographs and then renders an assessment and treatment plan.2 Hybrid teledermatology uses real-time audio and video conferencing for history taking, assessment and treatment plan, and patient education, with photographs sent asynchronously.3 Telemedicine may not be initially intuitive or easy to integrate into clinical practice, but with time and effort, it will complement your dermatology practice, making it run more efficiently.
Patient Satisfaction With Teledermatology
Studies generally have shown very high patient satisfaction rates and shorter wait times with teledermatology vs in-person visits; for example, in a systematic review of 15 teledermatology studies including 7781 patients, more than 80% of participants reported high satisfaction with their telemedicine visit, with up to 92% reporting that they would choose to do a televisit again.4 In a retrospective analysis of 615 Zocdoc physicians, 65% of whom were dermatologists, mean wait times were 2.4 days for virtual appointments compared with 11.7 days for in-person appointments.5 Similarly, in a retrospective single-institution study, mean wait times for televisits were 14.3 days compared with 34.7 days for in-person referrals.6
Follow-Up Visits for Nail Disorders Via Teledermatology
Teledermatology may be particularly well suited for treating patients with nail disorders. In a prospective observational study, Onyeka et al7 accessed 813 images from 63 dermatology patients via teledermatology over a 6-month period to assess distance, focus, brightness, background, and image quality; of them, 83% were rated as high quality. Notably, images of nail disorders, skin growths, or pigmentation disorders were rated as having better image quality than images of inflammatory skin conditions (odds ratio [OR], 4.2-12.9 [P<.005]).7 In a retrospective study of 107 telemedicine visits for nail disorders during the COVID-19 pandemic, patients with longitudinal melanonychia were recommended for in-person visits for physical examination and dermoscopy, as were patients with suspected onychomycosis, who required nail plate sampling for diagnostic confirmation; however, approximately half of visits did not require in-person follow-up, including those patients with confirmed onychomycosis.8 Onychomycosis patients could be examined for clinical improvement and counseled on medication compliance via telemedicine. Other patients who did not require in-person follow-ups were those with traumatic nail disorders such as subungual hematoma and retronychia as well as those with body‐focused repetitive behaviors, including habit-tic nail deformity, onychophagia, and onychotillomania.8
Patients undergoing nail biopsies to rule out malignancies or to diagnose inflammatory nail disorders also may be managed via telemedicine. Patients for whom nail biopsies are recommended often are anxious about the procedure, which may be due to portrayal of nail trauma in the media9 or lack of accurate information on nail biopsies online.10 Therefore, counseling via telemedicine about the details of the procedure in a patient-friendly way (eg, showing an animated video and narrating it11) can allay anxiety without the inconvenience, cost, and time missed from work associated with traveling to an in-person visit. In addition, postoperative counseling ideally is performed via telemedicine because complications following nail procedures are uncommon. In a retrospective study of 502 patients who underwent a nail biopsy at a single academic center, only 14 developed surgical site infections within 8 days on average (range, 5–13 days), with a higher infection risk in patients with type 2 diabetes mellitus (P<.0003).12
Advantages and Limitations
There are many benefits to incorporating telemedicine into dermatology practices, including reduced overhead costs, convenience and time saved for patients, and flexibility and improved work-life balance for dermatologists. In addition, because the number of in-person visits seen generally is fixed due to space constraints and work-hour restrictions, delegating follow-up visits to telemedicine can free up in-person slots for new patients and those needing procedures. However, there also are some inherent limitations to telemedicine: technology access, vision or hearing difficulties or low digital health literacy, or language barriers. In the prospective observational study by Onyeka et al7 analyzing 813 teledermatology images, patients aged 65 to 74 years sent in more clinically useful images (OR, 7.9) and images that were more often in focus (OR, 2.6) compared with patients older than 85 years.
Final Thoughts
Incorporation of telemedicine into dermatologic practice is a valuable tool for triaging patients with acute issues, improving patient care and health care access, making practices more efficient, and improving dermatologist flexibility and work-life balance. Further development of teledermatology to provide access to underserved populations prioritizing dermatologist reimbursement and progress on technologic innovations will make teledermatology even more useful in the coming years.
- He A, Ti Kim T, Nguyen KD. Utilization of teledermatology services for dermatological diagnoses during the COVID-19 pandemic. Arch Dermatol Res. 2023;315:1059-1062.
- Lee JJ, English JC 3rd. Teledermatology: a review and update. Am J Clin Dermatol. 2018;19:253-260.
- Wang RH, Barbieri JS, Kovarik CL, et al. Synchronous and asynchronous teledermatology: a narrative review of strengths and limitations. J Telemed Telecare. 2022;28:533-538.
- Miller J, Jones E. Shaping the future of teledermatology: a literature review of patient and provider satisfaction with synchronous teledermatology during the COVID-19 pandemic. Clin Exp Dermatol. 2022;47:1903-1909.
- Gu L, Xiang L, Lipner SR. Analysis of availability of online dermatology appointments during the COVID-19 pandemic. J Am Acad Dermatol. 2021;84:517-520.
- Wang RF, Trinidad J, Lawrence J, et al. Improved patient access and outcomes with the integration of an eConsult program (teledermatology) within a large academic medical center. J Am Acad Dermatol. 2019;83:1633-1638.
- Onyeka S, Kim J, Eid E, et al. Quality of images submitted by older patients to a teledermatology platform. Abstract presented at the Society of Investigative Dermatology Annual Meeting; May 15-18, 2024; Dallas, TX.
- Chang MJ, Stewart CR, Lipner SR. Retrospective study of nail telemedicine visits during the COVID-19 pandemic. Dermatol Ther. 2021;34:E14630.
- Albucker SJ, Falotico JM, Lipner SR. A real nail biter: a cross-sectional study of 75 nail trauma scenes in international films and television series. J Cutan Med Surg. 2023;27:288-291.
- Ishack S, Lipner SR. Evaluating the impact and educational value of YouTube videos on nail biopsy procedures. Cutis. 2020;105:148-149, E1.
- Hill RC, Ho B, Lipner SR. Assuaging patient anxiety about nail biopsies with an animated educational video. J Am Acad Dermatol. Published online March 29, 2024. doi:10.1016/j.jaad.2024.03.031.
- Axler E, Lu A, Darrell M, et al. Surgical site infections are uncommon following nail biopsies in a single-center case-control study of 502 patients. J Am Acad Dermatol. Published online May 15, 2024. doi:10.1016/j.jaad.2024.05.017
- He A, Ti Kim T, Nguyen KD. Utilization of teledermatology services for dermatological diagnoses during the COVID-19 pandemic. Arch Dermatol Res. 2023;315:1059-1062.
- Lee JJ, English JC 3rd. Teledermatology: a review and update. Am J Clin Dermatol. 2018;19:253-260.
- Wang RH, Barbieri JS, Kovarik CL, et al. Synchronous and asynchronous teledermatology: a narrative review of strengths and limitations. J Telemed Telecare. 2022;28:533-538.
- Miller J, Jones E. Shaping the future of teledermatology: a literature review of patient and provider satisfaction with synchronous teledermatology during the COVID-19 pandemic. Clin Exp Dermatol. 2022;47:1903-1909.
- Gu L, Xiang L, Lipner SR. Analysis of availability of online dermatology appointments during the COVID-19 pandemic. J Am Acad Dermatol. 2021;84:517-520.
- Wang RF, Trinidad J, Lawrence J, et al. Improved patient access and outcomes with the integration of an eConsult program (teledermatology) within a large academic medical center. J Am Acad Dermatol. 2019;83:1633-1638.
- Onyeka S, Kim J, Eid E, et al. Quality of images submitted by older patients to a teledermatology platform. Abstract presented at the Society of Investigative Dermatology Annual Meeting; May 15-18, 2024; Dallas, TX.
- Chang MJ, Stewart CR, Lipner SR. Retrospective study of nail telemedicine visits during the COVID-19 pandemic. Dermatol Ther. 2021;34:E14630.
- Albucker SJ, Falotico JM, Lipner SR. A real nail biter: a cross-sectional study of 75 nail trauma scenes in international films and television series. J Cutan Med Surg. 2023;27:288-291.
- Ishack S, Lipner SR. Evaluating the impact and educational value of YouTube videos on nail biopsy procedures. Cutis. 2020;105:148-149, E1.
- Hill RC, Ho B, Lipner SR. Assuaging patient anxiety about nail biopsies with an animated educational video. J Am Acad Dermatol. Published online March 29, 2024. doi:10.1016/j.jaad.2024.03.031.
- Axler E, Lu A, Darrell M, et al. Surgical site infections are uncommon following nail biopsies in a single-center case-control study of 502 patients. J Am Acad Dermatol. Published online May 15, 2024. doi:10.1016/j.jaad.2024.05.017
Practice Points
- Incorporation of telemedicine into dermatologic practice can improve patient access, reduce costs, and offer dermatologists flexibility and improved work-life balance.
- Patient satisfaction with telemedicine is exceedingly high, and teledermatology may be particularly well suited for caring for patients with nail disorders.