Cutis

To the Editor:

Skin cancer represents a notable health care burden of rising incidence.^1-3 Nondermatologist health care providers play a key role in skin cancer screening through the use of skin cancer examination (SCE)^1,4; however, several factors including poor diagnostic accuracy, low confidence, and lack of training have contributed to limited use of the SCE by these providers.^4,5 Therefore, it is important to identify and implement changes in the medical school curriculum that can facilitate improved use of SCE in clinical practice. We sought to examine factors in the medical school curriculum that influence skin cancer education.

A voluntary electronic survey was distributed through class email and social media to all medical student classes at 4 medical schools (Figure). Responses were collected between March 2 and April 20, 2020. Survey items assessed demographics and curricular factors that influence skin cancer education. Our study was approved by the Institutional Review Board for Human Research of the Medical University of South Carolina (Charleston, South Carolina).

Knowledge of the clinical features of melanoma was assessed by asking participants to correctly identify at least 5 of 6 pigmented lesions as concerning or not concerning for melanoma. Confidence in performing the SCE—the primary outcome—was measured by dichotomizing a 4-point Likert-type scale (“very confident” and “moderately confident” against “slightly confident” and “not at all confident”).

Logistic regression was used to examine curricular factors associated with confidence; descriptive statistics were used for remaining analyses. Analyses were performed using SAS 9.4 statistical software. Prior to analysis, responses from the University of South Carolina School of Medicine Greenville were excluded because the response rate was less than 20%.

The survey was distributed to 1524 students; 619 (40.6%) answered at least 1 question, with a variable response rate to each item (eTable 1). Most respondents were female (351 [56.7%]); 438 (70.8%) were White.

Most respondents said that they received 3 hours or less of general skin cancer (74.9%) or SCE-specific (93.0%) education by the end of their fourth year of medical training. Lecture was the most common method of instruction. Education was provided most often by dermatologists (48.6%), followed by general practice physicians (21.2%). Numerous (26.9%) fourth-year respondents reported that they had never observed SCE; even more (47.6%) had never performed SCE. Almost half of second- and third-year students (43.2% and 44.8%, respectively) considered themselves knowledgeable about the clinical features of melanoma, but only 31.9% of fourth-year students considered themselves knowledgeable.

Only 24.1% of fourth-year students reported confidence performing SCE (eTable 1). Students who received most of their instruction through real clinical encounters were 4.14 times more likely to be confident performing SCE than students who had been given lecture-based learning. Students who performed 1 to 3 SCE or 4 or more SCE were 3.02 and 32.25 times, respectively, more likely to be confident than students who had never performed SCE (eTable 2).

Consistent with a recent study,⁶ our results reflect the discrepancy between the burden and education of skin cancer. This is especially demonstrated by our cohort’s low confidence in performing SCE, a metric associated with both intention to perform and actual performance of SCE in practice.^4,5 We also observed a downward trend in knowledge among students who were about to enter residency, potentially indicating the need for longitudinal training.

Given curricular time constraints, it is essential that medical schools implement changes in learning that will have the greatest impact. Although our results strongly support the efficacy of hands-on clinical training, exposure to dermatology in the second half of medical school training is limited nationwide.⁶ Concentrated efforts to increase clinical exposure might help prepare future physicians in all specialties to combat the burden of this disease.

Limitations of our study include the potential for selection and recall biases. Although our survey spanned multiple institutions in different regions of the United States, results might not be universally representative.

Acknowledgments—We thank Dirk Elston, MD, and Amy Wahlquist, MS (both from Charleston, South Carolina), who helped facilitate the survey on which our research is based. We also acknowledge the assistance of Philip Carmon, MD (Columbia, South Carolina); Julie Flugel (Columbia, South Carolina); Algimantas Simpson, MD (Columbia, South Carolina); Nathan Jasperse, MD (Irvine, California); Jeremy Teruel, MD (Charleston, South Carolina); Alan Snyder, MD, MSCR (Charleston, South Carolina); John Bosland (Charleston, South Carolina); and Daniel Spangler (Greenville, South Carolina).

To the Editor:

Skin cancer represents a notable health care burden of rising incidence.^1-3 Nondermatologist health care providers play a key role in skin cancer screening through the use of skin cancer examination (SCE)^1,4; however, several factors including poor diagnostic accuracy, low confidence, and lack of training have contributed to limited use of the SCE by these providers.^4,5 Therefore, it is important to identify and implement changes in the medical school curriculum that can facilitate improved use of SCE in clinical practice. We sought to examine factors in the medical school curriculum that influence skin cancer education.

A voluntary electronic survey was distributed through class email and social media to all medical student classes at 4 medical schools (Figure). Responses were collected between March 2 and April 20, 2020. Survey items assessed demographics and curricular factors that influence skin cancer education. Our study was approved by the Institutional Review Board for Human Research of the Medical University of South Carolina (Charleston, South Carolina).

Knowledge of the clinical features of melanoma was assessed by asking participants to correctly identify at least 5 of 6 pigmented lesions as concerning or not concerning for melanoma. Confidence in performing the SCE—the primary outcome—was measured by dichotomizing a 4-point Likert-type scale (“very confident” and “moderately confident” against “slightly confident” and “not at all confident”).

Logistic regression was used to examine curricular factors associated with confidence; descriptive statistics were used for remaining analyses. Analyses were performed using SAS 9.4 statistical software. Prior to analysis, responses from the University of South Carolina School of Medicine Greenville were excluded because the response rate was less than 20%.

The survey was distributed to 1524 students; 619 (40.6%) answered at least 1 question, with a variable response rate to each item (eTable 1). Most respondents were female (351 [56.7%]); 438 (70.8%) were White.

Most respondents said that they received 3 hours or less of general skin cancer (74.9%) or SCE-specific (93.0%) education by the end of their fourth year of medical training. Lecture was the most common method of instruction. Education was provided most often by dermatologists (48.6%), followed by general practice physicians (21.2%). Numerous (26.9%) fourth-year respondents reported that they had never observed SCE; even more (47.6%) had never performed SCE. Almost half of second- and third-year students (43.2% and 44.8%, respectively) considered themselves knowledgeable about the clinical features of melanoma, but only 31.9% of fourth-year students considered themselves knowledgeable.

Only 24.1% of fourth-year students reported confidence performing SCE (eTable 1). Students who received most of their instruction through real clinical encounters were 4.14 times more likely to be confident performing SCE than students who had been given lecture-based learning. Students who performed 1 to 3 SCE or 4 or more SCE were 3.02 and 32.25 times, respectively, more likely to be confident than students who had never performed SCE (eTable 2).

Consistent with a recent study,⁶ our results reflect the discrepancy between the burden and education of skin cancer. This is especially demonstrated by our cohort’s low confidence in performing SCE, a metric associated with both intention to perform and actual performance of SCE in practice.^4,5 We also observed a downward trend in knowledge among students who were about to enter residency, potentially indicating the need for longitudinal training.

Given curricular time constraints, it is essential that medical schools implement changes in learning that will have the greatest impact. Although our results strongly support the efficacy of hands-on clinical training, exposure to dermatology in the second half of medical school training is limited nationwide.⁶ Concentrated efforts to increase clinical exposure might help prepare future physicians in all specialties to combat the burden of this disease.

Limitations of our study include the potential for selection and recall biases. Although our survey spanned multiple institutions in different regions of the United States, results might not be universally representative.

Acknowledgments—We thank Dirk Elston, MD, and Amy Wahlquist, MS (both from Charleston, South Carolina), who helped facilitate the survey on which our research is based. We also acknowledge the assistance of Philip Carmon, MD (Columbia, South Carolina); Julie Flugel (Columbia, South Carolina); Algimantas Simpson, MD (Columbia, South Carolina); Nathan Jasperse, MD (Irvine, California); Jeremy Teruel, MD (Charleston, South Carolina); Alan Snyder, MD, MSCR (Charleston, South Carolina); John Bosland (Charleston, South Carolina); and Daniel Spangler (Greenville, South Carolina).

To the Editor:

Skin cancer represents a notable health care burden of rising incidence.^1-3 Nondermatologist health care providers play a key role in skin cancer screening through the use of skin cancer examination (SCE)^1,4; however, several factors including poor diagnostic accuracy, low confidence, and lack of training have contributed to limited use of the SCE by these providers.^4,5 Therefore, it is important to identify and implement changes in the medical school curriculum that can facilitate improved use of SCE in clinical practice. We sought to examine factors in the medical school curriculum that influence skin cancer education.

A voluntary electronic survey was distributed through class email and social media to all medical student classes at 4 medical schools (Figure). Responses were collected between March 2 and April 20, 2020. Survey items assessed demographics and curricular factors that influence skin cancer education. Our study was approved by the Institutional Review Board for Human Research of the Medical University of South Carolina (Charleston, South Carolina).

Knowledge of the clinical features of melanoma was assessed by asking participants to correctly identify at least 5 of 6 pigmented lesions as concerning or not concerning for melanoma. Confidence in performing the SCE—the primary outcome—was measured by dichotomizing a 4-point Likert-type scale (“very confident” and “moderately confident” against “slightly confident” and “not at all confident”).

Logistic regression was used to examine curricular factors associated with confidence; descriptive statistics were used for remaining analyses. Analyses were performed using SAS 9.4 statistical software. Prior to analysis, responses from the University of South Carolina School of Medicine Greenville were excluded because the response rate was less than 20%.

The survey was distributed to 1524 students; 619 (40.6%) answered at least 1 question, with a variable response rate to each item (eTable 1). Most respondents were female (351 [56.7%]); 438 (70.8%) were White.

Most respondents said that they received 3 hours or less of general skin cancer (74.9%) or SCE-specific (93.0%) education by the end of their fourth year of medical training. Lecture was the most common method of instruction. Education was provided most often by dermatologists (48.6%), followed by general practice physicians (21.2%). Numerous (26.9%) fourth-year respondents reported that they had never observed SCE; even more (47.6%) had never performed SCE. Almost half of second- and third-year students (43.2% and 44.8%, respectively) considered themselves knowledgeable about the clinical features of melanoma, but only 31.9% of fourth-year students considered themselves knowledgeable.

Only 24.1% of fourth-year students reported confidence performing SCE (eTable 1). Students who received most of their instruction through real clinical encounters were 4.14 times more likely to be confident performing SCE than students who had been given lecture-based learning. Students who performed 1 to 3 SCE or 4 or more SCE were 3.02 and 32.25 times, respectively, more likely to be confident than students who had never performed SCE (eTable 2).

Consistent with a recent study,⁶ our results reflect the discrepancy between the burden and education of skin cancer. This is especially demonstrated by our cohort’s low confidence in performing SCE, a metric associated with both intention to perform and actual performance of SCE in practice.^4,5 We also observed a downward trend in knowledge among students who were about to enter residency, potentially indicating the need for longitudinal training.

Given curricular time constraints, it is essential that medical schools implement changes in learning that will have the greatest impact. Although our results strongly support the efficacy of hands-on clinical training, exposure to dermatology in the second half of medical school training is limited nationwide.⁶ Concentrated efforts to increase clinical exposure might help prepare future physicians in all specialties to combat the burden of this disease.

Limitations of our study include the potential for selection and recall biases. Although our survey spanned multiple institutions in different regions of the United States, results might not be universally representative.

Acknowledgments—We thank Dirk Elston, MD, and Amy Wahlquist, MS (both from Charleston, South Carolina), who helped facilitate the survey on which our research is based. We also acknowledge the assistance of Philip Carmon, MD (Columbia, South Carolina); Julie Flugel (Columbia, South Carolina); Algimantas Simpson, MD (Columbia, South Carolina); Nathan Jasperse, MD (Irvine, California); Jeremy Teruel, MD (Charleston, South Carolina); Alan Snyder, MD, MSCR (Charleston, South Carolina); John Bosland (Charleston, South Carolina); and Daniel Spangler (Greenville, South Carolina).

Background and Clinical Presentation

Seabather’s Eruption—Seabather’s eruption is a type I and IV hypersensitivity reaction caused by nematocysts of larval-stage thimble jellyfish (Linuche unguiculata), sea anemones (eg, Edwardsiella lineata), and larval cnidarians.¹Linuche unguiculata commonly is found along the southeast coast of the United States and in the Caribbean, the Gulf of Mexico, and the coasts of Florida; less commonly, it has been reported along the coasts of Brazil and Papua New Guinea. Edwardsiella lineata more commonly is seen along the East Coast of the United States.² Seabather’s eruption presents as numerous scattered, pruritic, red macules and papules (measuring 1 mm to 1.5 cm in size) distributed in areas covered by skin folds, wet clothing, or hair following exposure to marine water (Figure 1). This maculopapular rash generally appears shortly after exiting the water and can last up to several weeks in some cases.³ The cause for this delayed presentation is that the marine organisms become entrapped between the skin of the human contact and another object (eg, swimwear) but do not release their preformed antivenom until they are exposed to air after removal from the water, at which point the organisms die and cell lysis results in injection of the venom.

Diver’s Dermatitis—Diver’s dermatitis (also referred to as “swimmer’s itch”) is a type I and IV hypersensitivity reaction caused by schistosome cercariae released by aquatic snails.⁴ There are several different cercarial species known to be capable of causing diver dermatitis, but the most commonly implicated genera are Trichobilharzia and Gigantobilharzia. These parasites most commonly are found in freshwater lakes but also occur in oceans, particularly in brackish areas adjacent to freshwater access. Factors associated with increased concentrations of these parasites include shallow, slow-moving water and prolonged onshore wind causing accumulation near the shoreline. It also is thought that the snail host will shed greater concentrations of the parasitic worm in the morning hours and after prolonged exposure to sunlight.⁴ These flatworm trematodes have a 2-host life cycle. The snails function as intermediate hosts for the parasites before they enter their final host, which are birds. Humans only function as incidental and nonviable hosts for these worms. The parasites gain access to the human body by burrowing into exposed skin. Because the parasite is unable to survive on human hosts, it dies shortly after penetrating the skin, which leads to an intense inflammatory response causing symptoms of pruritus within hours of exposure (Figure 2). The initial eruption progresses over a few days into a diffuse, maculopapular, pruritic rash, similar to that seen in seabather’s eruption. This rash then regresses completely in 1 to 3 weeks. Subsequent exposure to the same parasite is associated with increased severity of future rashes, likely due to antibody-mediated sensitization.⁴

Photograph courtesy of Tomas Machacek, PhD (Prague, Czechia).

Diagnosis—Marine-derived dermatoses from various sources can present very similarly; thus, it is difficult to discern the specific etiology behind the clinical presentation. No commonly utilized imaging modalities can differentiate between seabather’s eruption and diver’s dermatitis, but eliciting a thorough patient history often can aid in differentiation of the cause of the eruption. For example, lesions located only on nonexposed areas of the skin increases the likelihood of seabather’s eruption due to nematocysts being trapped between clothing and the skin. In contrast, diver’s dermatitis generally appears on areas of the skin that were directly exposed to water and uncovered by clothing.⁵ Patient reports of a lack of symptoms until shortly after exiting the water further support a diagnosis of seabather’s eruption, as this delayed presentation of symptoms is caused by lysis of the culprit organisms following removal from the marine environment. The cell lysis is responsible for the widespread injection of preformed venom via the numerous nematocysts trapped between clothing and the patient’s body.¹

Treatment

For both conditions, the symptoms are treated with hydrocortisone or other topical steroid solutions in conjunction with oral hydroxyzine. Alternative treatments include calamine lotion with 1% menthol and nonsteroidal anti-inflammatory drugs. Taking baths with oatmeal, Epsom salts, or baking soda also may alleviate some of the pruritic symptoms.²

Prevention

The ability to diagnose the precise cause of these similar marine rashes can bring peace of mind to both patients and physicians regardless of their similar management strategies. Severe contact dermatitis of unknown etiology can be disconcerting for patients. Additionally, documenting the causes of marine rashes in particular geographic locations can be beneficial for establishing which organisms are most likely to affect visitors to those areas. This type of data collection can be utilized to develop preventative recommendations, such as deciding when to avoid the water. Education of the public can be done with the use of informational posters located near popular swimming areas and online public service announcements. Informing the general public about the dangers of entering the ocean, especially during certain times of the year when nematocyst-equipped sea creatures are in abundance, could serve to prevent numerous cases of seabather’s eruption. Likewise, advising against immersion in shallow, slow-moving water during the morning hours or after prolonged sun exposure in trematode-endemic areas could prevent numerous cases of diver’s dermatitis. Basic information on what to expect if afflicted by a marine rash also may reduce the number of emergency department visits for these conditions, thus providing economic benefit for patients and for hospitals since patients would better know how to acutely treat these rashes and lessen the patient load at hospital emergency departments. If individuals can assure themselves of the self-limited nature of these types of dermatoses, they may be less inclined to seek medical consultation.

Final Thoughts

As the climate continues to change, the incidence of marine rashes such as seabather’s eruption and diver’s dermatitis is expected to increase due to warmer surface temperatures causing more frequent and earlier blooms of L unguiculata and E lineata. Cases of diver’s dermatitis also could increase due to a longer season of more frequent human exposure from an increase in warmer temperatures. The projected uptick in incidences of these marine rashes makes understanding these pathologies even more pertinent for physicians.⁶ Increasing our understanding of the different types of marine rashes and their causes will help guide future recommendations for the general public when visiting the ocean.

Future research may wish to investigate unique ways in which to prevent contact between these organisms and humans. Past research on mice indicated that topical application of DEET (N,N-diethyl-meta-toluamide) prior to trematode exposure prevented penetration of the skin by parasitic worms.⁷ Future studies are needed to examine the effectiveness of this preventative technique on humans. For now, dermatologists may counsel our ocean-going patients on preventative behaviors as well as provide reassurance and symptomatic relief when they present to our clinics with marine rashes.

Background and Clinical Presentation

Seabather’s Eruption—Seabather’s eruption is a type I and IV hypersensitivity reaction caused by nematocysts of larval-stage thimble jellyfish (Linuche unguiculata), sea anemones (eg, Edwardsiella lineata), and larval cnidarians.¹Linuche unguiculata commonly is found along the southeast coast of the United States and in the Caribbean, the Gulf of Mexico, and the coasts of Florida; less commonly, it has been reported along the coasts of Brazil and Papua New Guinea. Edwardsiella lineata more commonly is seen along the East Coast of the United States.² Seabather’s eruption presents as numerous scattered, pruritic, red macules and papules (measuring 1 mm to 1.5 cm in size) distributed in areas covered by skin folds, wet clothing, or hair following exposure to marine water (Figure 1). This maculopapular rash generally appears shortly after exiting the water and can last up to several weeks in some cases.³ The cause for this delayed presentation is that the marine organisms become entrapped between the skin of the human contact and another object (eg, swimwear) but do not release their preformed antivenom until they are exposed to air after removal from the water, at which point the organisms die and cell lysis results in injection of the venom.

Diver’s Dermatitis—Diver’s dermatitis (also referred to as “swimmer’s itch”) is a type I and IV hypersensitivity reaction caused by schistosome cercariae released by aquatic snails.⁴ There are several different cercarial species known to be capable of causing diver dermatitis, but the most commonly implicated genera are Trichobilharzia and Gigantobilharzia. These parasites most commonly are found in freshwater lakes but also occur in oceans, particularly in brackish areas adjacent to freshwater access. Factors associated with increased concentrations of these parasites include shallow, slow-moving water and prolonged onshore wind causing accumulation near the shoreline. It also is thought that the snail host will shed greater concentrations of the parasitic worm in the morning hours and after prolonged exposure to sunlight.⁴ These flatworm trematodes have a 2-host life cycle. The snails function as intermediate hosts for the parasites before they enter their final host, which are birds. Humans only function as incidental and nonviable hosts for these worms. The parasites gain access to the human body by burrowing into exposed skin. Because the parasite is unable to survive on human hosts, it dies shortly after penetrating the skin, which leads to an intense inflammatory response causing symptoms of pruritus within hours of exposure (Figure 2). The initial eruption progresses over a few days into a diffuse, maculopapular, pruritic rash, similar to that seen in seabather’s eruption. This rash then regresses completely in 1 to 3 weeks. Subsequent exposure to the same parasite is associated with increased severity of future rashes, likely due to antibody-mediated sensitization.⁴

Photograph courtesy of Tomas Machacek, PhD (Prague, Czechia).

Diagnosis—Marine-derived dermatoses from various sources can present very similarly; thus, it is difficult to discern the specific etiology behind the clinical presentation. No commonly utilized imaging modalities can differentiate between seabather’s eruption and diver’s dermatitis, but eliciting a thorough patient history often can aid in differentiation of the cause of the eruption. For example, lesions located only on nonexposed areas of the skin increases the likelihood of seabather’s eruption due to nematocysts being trapped between clothing and the skin. In contrast, diver’s dermatitis generally appears on areas of the skin that were directly exposed to water and uncovered by clothing.⁵ Patient reports of a lack of symptoms until shortly after exiting the water further support a diagnosis of seabather’s eruption, as this delayed presentation of symptoms is caused by lysis of the culprit organisms following removal from the marine environment. The cell lysis is responsible for the widespread injection of preformed venom via the numerous nematocysts trapped between clothing and the patient’s body.¹

Treatment

For both conditions, the symptoms are treated with hydrocortisone or other topical steroid solutions in conjunction with oral hydroxyzine. Alternative treatments include calamine lotion with 1% menthol and nonsteroidal anti-inflammatory drugs. Taking baths with oatmeal, Epsom salts, or baking soda also may alleviate some of the pruritic symptoms.²

Prevention

The ability to diagnose the precise cause of these similar marine rashes can bring peace of mind to both patients and physicians regardless of their similar management strategies. Severe contact dermatitis of unknown etiology can be disconcerting for patients. Additionally, documenting the causes of marine rashes in particular geographic locations can be beneficial for establishing which organisms are most likely to affect visitors to those areas. This type of data collection can be utilized to develop preventative recommendations, such as deciding when to avoid the water. Education of the public can be done with the use of informational posters located near popular swimming areas and online public service announcements. Informing the general public about the dangers of entering the ocean, especially during certain times of the year when nematocyst-equipped sea creatures are in abundance, could serve to prevent numerous cases of seabather’s eruption. Likewise, advising against immersion in shallow, slow-moving water during the morning hours or after prolonged sun exposure in trematode-endemic areas could prevent numerous cases of diver’s dermatitis. Basic information on what to expect if afflicted by a marine rash also may reduce the number of emergency department visits for these conditions, thus providing economic benefit for patients and for hospitals since patients would better know how to acutely treat these rashes and lessen the patient load at hospital emergency departments. If individuals can assure themselves of the self-limited nature of these types of dermatoses, they may be less inclined to seek medical consultation.

Final Thoughts

As the climate continues to change, the incidence of marine rashes such as seabather’s eruption and diver’s dermatitis is expected to increase due to warmer surface temperatures causing more frequent and earlier blooms of L unguiculata and E lineata. Cases of diver’s dermatitis also could increase due to a longer season of more frequent human exposure from an increase in warmer temperatures. The projected uptick in incidences of these marine rashes makes understanding these pathologies even more pertinent for physicians.⁶ Increasing our understanding of the different types of marine rashes and their causes will help guide future recommendations for the general public when visiting the ocean.

Future research may wish to investigate unique ways in which to prevent contact between these organisms and humans. Past research on mice indicated that topical application of DEET (N,N-diethyl-meta-toluamide) prior to trematode exposure prevented penetration of the skin by parasitic worms.⁷ Future studies are needed to examine the effectiveness of this preventative technique on humans. For now, dermatologists may counsel our ocean-going patients on preventative behaviors as well as provide reassurance and symptomatic relief when they present to our clinics with marine rashes.

Background and Clinical Presentation

Seabather’s Eruption—Seabather’s eruption is a type I and IV hypersensitivity reaction caused by nematocysts of larval-stage thimble jellyfish (Linuche unguiculata), sea anemones (eg, Edwardsiella lineata), and larval cnidarians.¹Linuche unguiculata commonly is found along the southeast coast of the United States and in the Caribbean, the Gulf of Mexico, and the coasts of Florida; less commonly, it has been reported along the coasts of Brazil and Papua New Guinea. Edwardsiella lineata more commonly is seen along the East Coast of the United States.² Seabather’s eruption presents as numerous scattered, pruritic, red macules and papules (measuring 1 mm to 1.5 cm in size) distributed in areas covered by skin folds, wet clothing, or hair following exposure to marine water (Figure 1). This maculopapular rash generally appears shortly after exiting the water and can last up to several weeks in some cases.³ The cause for this delayed presentation is that the marine organisms become entrapped between the skin of the human contact and another object (eg, swimwear) but do not release their preformed antivenom until they are exposed to air after removal from the water, at which point the organisms die and cell lysis results in injection of the venom.

Diver’s Dermatitis—Diver’s dermatitis (also referred to as “swimmer’s itch”) is a type I and IV hypersensitivity reaction caused by schistosome cercariae released by aquatic snails.⁴ There are several different cercarial species known to be capable of causing diver dermatitis, but the most commonly implicated genera are Trichobilharzia and Gigantobilharzia. These parasites most commonly are found in freshwater lakes but also occur in oceans, particularly in brackish areas adjacent to freshwater access. Factors associated with increased concentrations of these parasites include shallow, slow-moving water and prolonged onshore wind causing accumulation near the shoreline. It also is thought that the snail host will shed greater concentrations of the parasitic worm in the morning hours and after prolonged exposure to sunlight.⁴ These flatworm trematodes have a 2-host life cycle. The snails function as intermediate hosts for the parasites before they enter their final host, which are birds. Humans only function as incidental and nonviable hosts for these worms. The parasites gain access to the human body by burrowing into exposed skin. Because the parasite is unable to survive on human hosts, it dies shortly after penetrating the skin, which leads to an intense inflammatory response causing symptoms of pruritus within hours of exposure (Figure 2). The initial eruption progresses over a few days into a diffuse, maculopapular, pruritic rash, similar to that seen in seabather’s eruption. This rash then regresses completely in 1 to 3 weeks. Subsequent exposure to the same parasite is associated with increased severity of future rashes, likely due to antibody-mediated sensitization.⁴

Photograph courtesy of Tomas Machacek, PhD (Prague, Czechia).

Diagnosis—Marine-derived dermatoses from various sources can present very similarly; thus, it is difficult to discern the specific etiology behind the clinical presentation. No commonly utilized imaging modalities can differentiate between seabather’s eruption and diver’s dermatitis, but eliciting a thorough patient history often can aid in differentiation of the cause of the eruption. For example, lesions located only on nonexposed areas of the skin increases the likelihood of seabather’s eruption due to nematocysts being trapped between clothing and the skin. In contrast, diver’s dermatitis generally appears on areas of the skin that were directly exposed to water and uncovered by clothing.⁵ Patient reports of a lack of symptoms until shortly after exiting the water further support a diagnosis of seabather’s eruption, as this delayed presentation of symptoms is caused by lysis of the culprit organisms following removal from the marine environment. The cell lysis is responsible for the widespread injection of preformed venom via the numerous nematocysts trapped between clothing and the patient’s body.¹

Treatment

For both conditions, the symptoms are treated with hydrocortisone or other topical steroid solutions in conjunction with oral hydroxyzine. Alternative treatments include calamine lotion with 1% menthol and nonsteroidal anti-inflammatory drugs. Taking baths with oatmeal, Epsom salts, or baking soda also may alleviate some of the pruritic symptoms.²

Prevention

The ability to diagnose the precise cause of these similar marine rashes can bring peace of mind to both patients and physicians regardless of their similar management strategies. Severe contact dermatitis of unknown etiology can be disconcerting for patients. Additionally, documenting the causes of marine rashes in particular geographic locations can be beneficial for establishing which organisms are most likely to affect visitors to those areas. This type of data collection can be utilized to develop preventative recommendations, such as deciding when to avoid the water. Education of the public can be done with the use of informational posters located near popular swimming areas and online public service announcements. Informing the general public about the dangers of entering the ocean, especially during certain times of the year when nematocyst-equipped sea creatures are in abundance, could serve to prevent numerous cases of seabather’s eruption. Likewise, advising against immersion in shallow, slow-moving water during the morning hours or after prolonged sun exposure in trematode-endemic areas could prevent numerous cases of diver’s dermatitis. Basic information on what to expect if afflicted by a marine rash also may reduce the number of emergency department visits for these conditions, thus providing economic benefit for patients and for hospitals since patients would better know how to acutely treat these rashes and lessen the patient load at hospital emergency departments. If individuals can assure themselves of the self-limited nature of these types of dermatoses, they may be less inclined to seek medical consultation.

Final Thoughts

As the climate continues to change, the incidence of marine rashes such as seabather’s eruption and diver’s dermatitis is expected to increase due to warmer surface temperatures causing more frequent and earlier blooms of L unguiculata and E lineata. Cases of diver’s dermatitis also could increase due to a longer season of more frequent human exposure from an increase in warmer temperatures. The projected uptick in incidences of these marine rashes makes understanding these pathologies even more pertinent for physicians.⁶ Increasing our understanding of the different types of marine rashes and their causes will help guide future recommendations for the general public when visiting the ocean.

Future research may wish to investigate unique ways in which to prevent contact between these organisms and humans. Past research on mice indicated that topical application of DEET (N,N-diethyl-meta-toluamide) prior to trematode exposure prevented penetration of the skin by parasitic worms.⁷ Future studies are needed to examine the effectiveness of this preventative technique on humans. For now, dermatologists may counsel our ocean-going patients on preventative behaviors as well as provide reassurance and symptomatic relief when they present to our clinics with marine rashes.

The Diagnosis: Metastatic Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) is a common genitourinary system malignancy with incidence peaking between 50 and 70 years of age and a male predominance.¹ The clear cell variant is the most common subtype of RCC, accounting for 70% to 75% of all cases. It is known to be a highly aggressive malignancy that frequently metastasizes to the lungs, lymphatics, bones, liver, and brain.^2,3 Approximately 20% to 50% of patients with RCC eventually will develop metastasis after nephrectomy.⁴ Survival with metastatic RCC to any site typically is in the range of 10 to 22 months.^5,6 Cutaneous metastases of RCC rarely have been reported in the literature (3%–6% of cases⁷) and most commonly are found on the scalp, followed by the chest or abdomen. ⁸ Cutaneous metastases generally are regarded as a late manifestation of the disease with a very poor prognosis. ⁹ It is unusual to identify cutaneous RCC metastasis without known RCC or other symptoms consistent with advanced RCC, such as hematuria or abdominal/flank pain. Renal cell carcinoma accounts for an estimated 6% to 7% of all cutaneous metastatic lesions.¹⁰ Cutaneous metastatic lesions of RCC often are solitary and grow rapidly, with the clinical appearance of an erythematous or violaceous, nodular, highly vascular, and often hemorrhagic growth.^9,11,12

Following the histologic diagnosis of metastatic clear cell RCC, our patient was referred to medical oncology for further workup. Magnetic resonance imaging and a positron emission tomography scan demonstrated widespread disease with a 7-cm left renal mass, liver and lung metastases, and bilateral mediastinal lymphadenopathy. The patient was started on combination immunotherapy as a palliative treatment given the widespread disease.

Histologically, clear cell RCC is characterized by lipid and glycogen-rich cells with ample cytoplasm and a well-developed vascular network, which often is thin walled with a chicken wire–like architecture. Metastatic clear cell RCC tumor cells may form glandular, acinar, or papillary structures with variable lymphocytic inflammatory infiltrates and abundant capillary formation. Immunohistochemically, the tumor cells should demonstrate positivity for paired box gene 8, PAX8, and RCC marker antigen.¹³ Vimentin and carcinoembryonic antigen may be utilized to distinguish from hidradenoma as carcinoembryonic antigen will be positive in hidradenoma and vimentin will be negative.¹⁴ Renal cell carcinoma also has a common molecular signature of von Hippel-Lindau tumor suppressor gene inactivation as well as upregulation of hypoxia inducible factor and vascular endothelial growth factor.¹⁵

Balloon cell nevi often clinically present in young patients as bicolored nevi that sometimes are polypoid or verrucous in appearance with central yellow globules surrounded by a peripheral reticular pattern on dermoscopy. Histologically, balloon cell nevi are characterized by large cells with small, round, centrally located basophilic nuclei and clear foamy cytoplasm (Figure 1), which are thought to be formed by progressive vacuolization of melanocytes due to the enlargement and disintegration of melanosomes. This ballooning change reflects an seen in malignant melanoma, in which case nuclear pleomorphism, atypia, and increased mitotic activity also are observed. The prominent vascular network characteristic of RCC typically is not present.¹⁶

Clear cell hidradenomas are benign skin appendage tumors that often present as small, firm, solitary dermal nodules that may extend into the subcutaneous fat. They have a predilection for the head, face, and arms and demonstrate 2 predominant cell types, including a polyhedral cell with a rounded nucleus and slightly basophilic cytoplasm as well as a round cell with clear cytoplasm and bland nuclei (Figure 2). The latter cell type is less common, representing the predominant cell type in less than one-third of hidradenomas, and can present a diagnostic quandary based on histologic similarity to other clear cell neoplasms. The clear cells contain glycogen but no lipid. Ductlike structures often are present, and the intervening stroma varies from delicate vascularized cords of fibrous tissue to dense hyalinized collagen. Immunohistochemistry may be required for definitive diagnosis, and clear cell hidradenomas should react with monoclonal antibodies that label both eccrine and apocrine secretory elements, such as cytokeratins 6/18, 7, and 8/18.¹⁷

Pyogenic granulomas (also referred to as lobular capillary hemangiomas) are common and present clinically as rapidly growing, polypoid, red masses surrounded by a thickened epidermis that often are found on the fingers or lips. This entity is benign and often regresses spontaneously. Histologically, pyogenic granulomas are characterized by a lobular pattern of vascular proliferation associated with edema and inflammation resembling granulation tissue, with acanthosis and hyperkeratosis at the edges of the lesion (Figure 3).¹⁸

Sebaceous carcinoma is a locally aggressive malignant neoplasm arising from the cells of the sebaceous glands and occurring most commonly in the periorbital area. This neoplasm most often affects older adults, with a mean age at diagnosis of 63 to 77 years. It commonly presents as a solitary nodule with yellowish discoloration and madarosis, which is a key distinguishing feature to differentiate this entity from a chalazion or hordeolum. Histologically, sebaceous carcinoma is a dermal-based infiltrative, nodular tumor with varying degrees of clear cell changes—well-differentiated tumors show more clear cell change as compared to more poorly differentiated variants—along with basaloid or squamous features and abundant mitotic activity (Figure 4), which may be useful in distinguishing it from the other entities in the clear cell neoplasm differential.^19-22

The Diagnosis: Metastatic Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) is a common genitourinary system malignancy with incidence peaking between 50 and 70 years of age and a male predominance.¹ The clear cell variant is the most common subtype of RCC, accounting for 70% to 75% of all cases. It is known to be a highly aggressive malignancy that frequently metastasizes to the lungs, lymphatics, bones, liver, and brain.^2,3 Approximately 20% to 50% of patients with RCC eventually will develop metastasis after nephrectomy.⁴ Survival with metastatic RCC to any site typically is in the range of 10 to 22 months.^5,6 Cutaneous metastases of RCC rarely have been reported in the literature (3%–6% of cases⁷) and most commonly are found on the scalp, followed by the chest or abdomen. ⁸ Cutaneous metastases generally are regarded as a late manifestation of the disease with a very poor prognosis. ⁹ It is unusual to identify cutaneous RCC metastasis without known RCC or other symptoms consistent with advanced RCC, such as hematuria or abdominal/flank pain. Renal cell carcinoma accounts for an estimated 6% to 7% of all cutaneous metastatic lesions.¹⁰ Cutaneous metastatic lesions of RCC often are solitary and grow rapidly, with the clinical appearance of an erythematous or violaceous, nodular, highly vascular, and often hemorrhagic growth.^9,11,12

Following the histologic diagnosis of metastatic clear cell RCC, our patient was referred to medical oncology for further workup. Magnetic resonance imaging and a positron emission tomography scan demonstrated widespread disease with a 7-cm left renal mass, liver and lung metastases, and bilateral mediastinal lymphadenopathy. The patient was started on combination immunotherapy as a palliative treatment given the widespread disease.

Histologically, clear cell RCC is characterized by lipid and glycogen-rich cells with ample cytoplasm and a well-developed vascular network, which often is thin walled with a chicken wire–like architecture. Metastatic clear cell RCC tumor cells may form glandular, acinar, or papillary structures with variable lymphocytic inflammatory infiltrates and abundant capillary formation. Immunohistochemically, the tumor cells should demonstrate positivity for paired box gene 8, PAX8, and RCC marker antigen.¹³ Vimentin and carcinoembryonic antigen may be utilized to distinguish from hidradenoma as carcinoembryonic antigen will be positive in hidradenoma and vimentin will be negative.¹⁴ Renal cell carcinoma also has a common molecular signature of von Hippel-Lindau tumor suppressor gene inactivation as well as upregulation of hypoxia inducible factor and vascular endothelial growth factor.¹⁵

Balloon cell nevi often clinically present in young patients as bicolored nevi that sometimes are polypoid or verrucous in appearance with central yellow globules surrounded by a peripheral reticular pattern on dermoscopy. Histologically, balloon cell nevi are characterized by large cells with small, round, centrally located basophilic nuclei and clear foamy cytoplasm (Figure 1), which are thought to be formed by progressive vacuolization of melanocytes due to the enlargement and disintegration of melanosomes. This ballooning change reflects an seen in malignant melanoma, in which case nuclear pleomorphism, atypia, and increased mitotic activity also are observed. The prominent vascular network characteristic of RCC typically is not present.¹⁶

Clear cell hidradenomas are benign skin appendage tumors that often present as small, firm, solitary dermal nodules that may extend into the subcutaneous fat. They have a predilection for the head, face, and arms and demonstrate 2 predominant cell types, including a polyhedral cell with a rounded nucleus and slightly basophilic cytoplasm as well as a round cell with clear cytoplasm and bland nuclei (Figure 2). The latter cell type is less common, representing the predominant cell type in less than one-third of hidradenomas, and can present a diagnostic quandary based on histologic similarity to other clear cell neoplasms. The clear cells contain glycogen but no lipid. Ductlike structures often are present, and the intervening stroma varies from delicate vascularized cords of fibrous tissue to dense hyalinized collagen. Immunohistochemistry may be required for definitive diagnosis, and clear cell hidradenomas should react with monoclonal antibodies that label both eccrine and apocrine secretory elements, such as cytokeratins 6/18, 7, and 8/18.¹⁷

Pyogenic granulomas (also referred to as lobular capillary hemangiomas) are common and present clinically as rapidly growing, polypoid, red masses surrounded by a thickened epidermis that often are found on the fingers or lips. This entity is benign and often regresses spontaneously. Histologically, pyogenic granulomas are characterized by a lobular pattern of vascular proliferation associated with edema and inflammation resembling granulation tissue, with acanthosis and hyperkeratosis at the edges of the lesion (Figure 3).¹⁸

Sebaceous carcinoma is a locally aggressive malignant neoplasm arising from the cells of the sebaceous glands and occurring most commonly in the periorbital area. This neoplasm most often affects older adults, with a mean age at diagnosis of 63 to 77 years. It commonly presents as a solitary nodule with yellowish discoloration and madarosis, which is a key distinguishing feature to differentiate this entity from a chalazion or hordeolum. Histologically, sebaceous carcinoma is a dermal-based infiltrative, nodular tumor with varying degrees of clear cell changes—well-differentiated tumors show more clear cell change as compared to more poorly differentiated variants—along with basaloid or squamous features and abundant mitotic activity (Figure 4), which may be useful in distinguishing it from the other entities in the clear cell neoplasm differential.^19-22

The Diagnosis: Metastatic Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) is a common genitourinary system malignancy with incidence peaking between 50 and 70 years of age and a male predominance.¹ The clear cell variant is the most common subtype of RCC, accounting for 70% to 75% of all cases. It is known to be a highly aggressive malignancy that frequently metastasizes to the lungs, lymphatics, bones, liver, and brain.^2,3 Approximately 20% to 50% of patients with RCC eventually will develop metastasis after nephrectomy.⁴ Survival with metastatic RCC to any site typically is in the range of 10 to 22 months.^5,6 Cutaneous metastases of RCC rarely have been reported in the literature (3%–6% of cases⁷) and most commonly are found on the scalp, followed by the chest or abdomen. ⁸ Cutaneous metastases generally are regarded as a late manifestation of the disease with a very poor prognosis. ⁹ It is unusual to identify cutaneous RCC metastasis without known RCC or other symptoms consistent with advanced RCC, such as hematuria or abdominal/flank pain. Renal cell carcinoma accounts for an estimated 6% to 7% of all cutaneous metastatic lesions.¹⁰ Cutaneous metastatic lesions of RCC often are solitary and grow rapidly, with the clinical appearance of an erythematous or violaceous, nodular, highly vascular, and often hemorrhagic growth.^9,11,12

Following the histologic diagnosis of metastatic clear cell RCC, our patient was referred to medical oncology for further workup. Magnetic resonance imaging and a positron emission tomography scan demonstrated widespread disease with a 7-cm left renal mass, liver and lung metastases, and bilateral mediastinal lymphadenopathy. The patient was started on combination immunotherapy as a palliative treatment given the widespread disease.

Histologically, clear cell RCC is characterized by lipid and glycogen-rich cells with ample cytoplasm and a well-developed vascular network, which often is thin walled with a chicken wire–like architecture. Metastatic clear cell RCC tumor cells may form glandular, acinar, or papillary structures with variable lymphocytic inflammatory infiltrates and abundant capillary formation. Immunohistochemically, the tumor cells should demonstrate positivity for paired box gene 8, PAX8, and RCC marker antigen.¹³ Vimentin and carcinoembryonic antigen may be utilized to distinguish from hidradenoma as carcinoembryonic antigen will be positive in hidradenoma and vimentin will be negative.¹⁴ Renal cell carcinoma also has a common molecular signature of von Hippel-Lindau tumor suppressor gene inactivation as well as upregulation of hypoxia inducible factor and vascular endothelial growth factor.¹⁵

Balloon cell nevi often clinically present in young patients as bicolored nevi that sometimes are polypoid or verrucous in appearance with central yellow globules surrounded by a peripheral reticular pattern on dermoscopy. Histologically, balloon cell nevi are characterized by large cells with small, round, centrally located basophilic nuclei and clear foamy cytoplasm (Figure 1), which are thought to be formed by progressive vacuolization of melanocytes due to the enlargement and disintegration of melanosomes. This ballooning change reflects an seen in malignant melanoma, in which case nuclear pleomorphism, atypia, and increased mitotic activity also are observed. The prominent vascular network characteristic of RCC typically is not present.¹⁶

Clear cell hidradenomas are benign skin appendage tumors that often present as small, firm, solitary dermal nodules that may extend into the subcutaneous fat. They have a predilection for the head, face, and arms and demonstrate 2 predominant cell types, including a polyhedral cell with a rounded nucleus and slightly basophilic cytoplasm as well as a round cell with clear cytoplasm and bland nuclei (Figure 2). The latter cell type is less common, representing the predominant cell type in less than one-third of hidradenomas, and can present a diagnostic quandary based on histologic similarity to other clear cell neoplasms. The clear cells contain glycogen but no lipid. Ductlike structures often are present, and the intervening stroma varies from delicate vascularized cords of fibrous tissue to dense hyalinized collagen. Immunohistochemistry may be required for definitive diagnosis, and clear cell hidradenomas should react with monoclonal antibodies that label both eccrine and apocrine secretory elements, such as cytokeratins 6/18, 7, and 8/18.¹⁷

Pyogenic granulomas (also referred to as lobular capillary hemangiomas) are common and present clinically as rapidly growing, polypoid, red masses surrounded by a thickened epidermis that often are found on the fingers or lips. This entity is benign and often regresses spontaneously. Histologically, pyogenic granulomas are characterized by a lobular pattern of vascular proliferation associated with edema and inflammation resembling granulation tissue, with acanthosis and hyperkeratosis at the edges of the lesion (Figure 3).¹⁸

Sebaceous carcinoma is a locally aggressive malignant neoplasm arising from the cells of the sebaceous glands and occurring most commonly in the periorbital area. This neoplasm most often affects older adults, with a mean age at diagnosis of 63 to 77 years. It commonly presents as a solitary nodule with yellowish discoloration and madarosis, which is a key distinguishing feature to differentiate this entity from a chalazion or hordeolum. Histologically, sebaceous carcinoma is a dermal-based infiltrative, nodular tumor with varying degrees of clear cell changes—well-differentiated tumors show more clear cell change as compared to more poorly differentiated variants—along with basaloid or squamous features and abundant mitotic activity (Figure 4), which may be useful in distinguishing it from the other entities in the clear cell neoplasm differential.^19-22

The Diagnosis: Lupus Erythematosus Tumidus

Histopathologic evaluation of a punch biopsy revealed focal dermal mucin deposition and CD123+ discrete clusters of plasmacytoid dendritic cells without interface changes (Figure 1), favoring a diagnosis of lupus erythematosus tumidus (LET) in our patient. There was no clinical improvement in symptoms when she previously was treated with topical antifungals or class III corticosteroid creams. Tacrolimus ointment 0.1% twice daily for 1 month did not result in substantial improvement in the appearance of the plaque, and it spontaneously resolved after 2 to 3 months. She declined treatment with hydroxychloroquine.

Lupus erythematosus tumidus is an uncommon subtype of chronic cutaneous lupus erythematosus with no distinct etiology. It is clinically characterized by edematous, urticarial, single or multiple plaques with a smooth surface affecting sun-exposed areas that can last for months to years.¹ In contrast to other variations of chronic cutaneous lupus such as discoid lupus erythematosus, LET lesions lack surface papulosquamous features such as scaling, atrophy, and follicular plugging.^1-4 Based solely on histologic findings, LET may be indistinguishable from reticular erythematous mucinosis and Jessner lymphocytic infiltration of the skin (JLIS) due to a similar lack of epidermal involvement and presence of a perivascular lymphocytic infiltrate (Figure 2).

The average age at disease onset is 36 years, nearly the same as that described in discoid lupus erythematosus.⁴ Lupus erythematosus tumidus has a favorable prognosis and commonly presents without other autoimmune signs, serologic abnormalities, or gender preference, with concomitant systemic lupus erythematosus sometimes reported.⁵

The absence of clinical and histological epidermal involvement are the most important clues to aid in the diagnosis. It has been postulated that JLIS could be an early cutaneous manifestation of LET.⁶ The differential diagnosis also may include erythema annulare centrifugum, granuloma annulare, and urticarial vasculitis. Lesions typically respond well to photoprotection, topical corticosteroids, and/or antimalarials. The addition of tacrolimus ointment 0.1% may result in complete regression without recurrence.⁷

Erythema annulare centrifugum is a reactive erythema that classically begins as a pink papule that gradually enlarges to form an annular erythematous plaque with a fine trailing scale that may recur.⁸ The histopathology of erythema annulare centrifugum shares features seen in LET, making the diagnosis difficult; however, secondary changes to the epidermis (eg, spongiosis, hyperkeratosis) may be seen. This condition has been associated with lymphoproliferative malignancies.⁸

Reticular erythematous mucinosis is clinically distinguished from LET, as it presents as reticular, rather than arciform, erythematous macules, papules, or plaques that may be asymptomatic or pruritic.⁹ Histopathology typically shows more superficial mucin deposition than in LET as well as superficial to mid-dermal perivascular and periadnexal lymphocytic infiltrates. Reticular erythematous mucinosis more frequently is reported in women in their 30s and 40s and has been associated with UV exposure and hormonal triggers, such as oral contraceptive medications and pregnancy.⁹

Granuloma annulare typically presents as asymptomatic, erythematous, annular plaques or papules in young women.¹⁰ There are several histologic subtypes that show focal collagen degeneration, inflammation with palisaded or interstitial histiocytes, and mucin deposition, regardless of clinical presentation. Granuloma annulare has been associated with systemic diseases including type 2 diabetes mellitus and thyroid disease. Localized granuloma annulare most commonly presents on the dorsal aspects of the hands or feet.¹⁰

We present a case of LET on the face. Although histologically similar to other dermatoses, LET often lacks epidermal involvement and presents on sun-exposed areas of the body. Jessner lymphocytic infiltration of the skin also should be considered in the differential, as there is an overlap of clinical and histopathological features; JLIS lacks mucin deposits.⁶ This case reinforces the importance of correlating clinical with histopathologic findings. Our patient was treated with tacrolimus ointment 0.1%, and the plaque eventually resolved in 2 to 3 months without recurrence. This condition should be included in the differential diagnosis of recurring annular plaques on sunexposed areas, particularly in middle-aged adults, even in the absence of systemic involvement.

The Diagnosis: Lupus Erythematosus Tumidus

Histopathologic evaluation of a punch biopsy revealed focal dermal mucin deposition and CD123+ discrete clusters of plasmacytoid dendritic cells without interface changes (Figure 1), favoring a diagnosis of lupus erythematosus tumidus (LET) in our patient. There was no clinical improvement in symptoms when she previously was treated with topical antifungals or class III corticosteroid creams. Tacrolimus ointment 0.1% twice daily for 1 month did not result in substantial improvement in the appearance of the plaque, and it spontaneously resolved after 2 to 3 months. She declined treatment with hydroxychloroquine.

Lupus erythematosus tumidus is an uncommon subtype of chronic cutaneous lupus erythematosus with no distinct etiology. It is clinically characterized by edematous, urticarial, single or multiple plaques with a smooth surface affecting sun-exposed areas that can last for months to years.¹ In contrast to other variations of chronic cutaneous lupus such as discoid lupus erythematosus, LET lesions lack surface papulosquamous features such as scaling, atrophy, and follicular plugging.^1-4 Based solely on histologic findings, LET may be indistinguishable from reticular erythematous mucinosis and Jessner lymphocytic infiltration of the skin (JLIS) due to a similar lack of epidermal involvement and presence of a perivascular lymphocytic infiltrate (Figure 2).

The average age at disease onset is 36 years, nearly the same as that described in discoid lupus erythematosus.⁴ Lupus erythematosus tumidus has a favorable prognosis and commonly presents without other autoimmune signs, serologic abnormalities, or gender preference, with concomitant systemic lupus erythematosus sometimes reported.⁵

The absence of clinical and histological epidermal involvement are the most important clues to aid in the diagnosis. It has been postulated that JLIS could be an early cutaneous manifestation of LET.⁶ The differential diagnosis also may include erythema annulare centrifugum, granuloma annulare, and urticarial vasculitis. Lesions typically respond well to photoprotection, topical corticosteroids, and/or antimalarials. The addition of tacrolimus ointment 0.1% may result in complete regression without recurrence.⁷

Erythema annulare centrifugum is a reactive erythema that classically begins as a pink papule that gradually enlarges to form an annular erythematous plaque with a fine trailing scale that may recur.⁸ The histopathology of erythema annulare centrifugum shares features seen in LET, making the diagnosis difficult; however, secondary changes to the epidermis (eg, spongiosis, hyperkeratosis) may be seen. This condition has been associated with lymphoproliferative malignancies.⁸

Reticular erythematous mucinosis is clinically distinguished from LET, as it presents as reticular, rather than arciform, erythematous macules, papules, or plaques that may be asymptomatic or pruritic.⁹ Histopathology typically shows more superficial mucin deposition than in LET as well as superficial to mid-dermal perivascular and periadnexal lymphocytic infiltrates. Reticular erythematous mucinosis more frequently is reported in women in their 30s and 40s and has been associated with UV exposure and hormonal triggers, such as oral contraceptive medications and pregnancy.⁹

Granuloma annulare typically presents as asymptomatic, erythematous, annular plaques or papules in young women.¹⁰ There are several histologic subtypes that show focal collagen degeneration, inflammation with palisaded or interstitial histiocytes, and mucin deposition, regardless of clinical presentation. Granuloma annulare has been associated with systemic diseases including type 2 diabetes mellitus and thyroid disease. Localized granuloma annulare most commonly presents on the dorsal aspects of the hands or feet.¹⁰

We present a case of LET on the face. Although histologically similar to other dermatoses, LET often lacks epidermal involvement and presents on sun-exposed areas of the body. Jessner lymphocytic infiltration of the skin also should be considered in the differential, as there is an overlap of clinical and histopathological features; JLIS lacks mucin deposits.⁶ This case reinforces the importance of correlating clinical with histopathologic findings. Our patient was treated with tacrolimus ointment 0.1%, and the plaque eventually resolved in 2 to 3 months without recurrence. This condition should be included in the differential diagnosis of recurring annular plaques on sunexposed areas, particularly in middle-aged adults, even in the absence of systemic involvement.

The Diagnosis: Lupus Erythematosus Tumidus

Histopathologic evaluation of a punch biopsy revealed focal dermal mucin deposition and CD123+ discrete clusters of plasmacytoid dendritic cells without interface changes (Figure 1), favoring a diagnosis of lupus erythematosus tumidus (LET) in our patient. There was no clinical improvement in symptoms when she previously was treated with topical antifungals or class III corticosteroid creams. Tacrolimus ointment 0.1% twice daily for 1 month did not result in substantial improvement in the appearance of the plaque, and it spontaneously resolved after 2 to 3 months. She declined treatment with hydroxychloroquine.

Lupus erythematosus tumidus is an uncommon subtype of chronic cutaneous lupus erythematosus with no distinct etiology. It is clinically characterized by edematous, urticarial, single or multiple plaques with a smooth surface affecting sun-exposed areas that can last for months to years.¹ In contrast to other variations of chronic cutaneous lupus such as discoid lupus erythematosus, LET lesions lack surface papulosquamous features such as scaling, atrophy, and follicular plugging.^1-4 Based solely on histologic findings, LET may be indistinguishable from reticular erythematous mucinosis and Jessner lymphocytic infiltration of the skin (JLIS) due to a similar lack of epidermal involvement and presence of a perivascular lymphocytic infiltrate (Figure 2).

The average age at disease onset is 36 years, nearly the same as that described in discoid lupus erythematosus.⁴ Lupus erythematosus tumidus has a favorable prognosis and commonly presents without other autoimmune signs, serologic abnormalities, or gender preference, with concomitant systemic lupus erythematosus sometimes reported.⁵

The absence of clinical and histological epidermal involvement are the most important clues to aid in the diagnosis. It has been postulated that JLIS could be an early cutaneous manifestation of LET.⁶ The differential diagnosis also may include erythema annulare centrifugum, granuloma annulare, and urticarial vasculitis. Lesions typically respond well to photoprotection, topical corticosteroids, and/or antimalarials. The addition of tacrolimus ointment 0.1% may result in complete regression without recurrence.⁷

Erythema annulare centrifugum is a reactive erythema that classically begins as a pink papule that gradually enlarges to form an annular erythematous plaque with a fine trailing scale that may recur.⁸ The histopathology of erythema annulare centrifugum shares features seen in LET, making the diagnosis difficult; however, secondary changes to the epidermis (eg, spongiosis, hyperkeratosis) may be seen. This condition has been associated with lymphoproliferative malignancies.⁸

Reticular erythematous mucinosis is clinically distinguished from LET, as it presents as reticular, rather than arciform, erythematous macules, papules, or plaques that may be asymptomatic or pruritic.⁹ Histopathology typically shows more superficial mucin deposition than in LET as well as superficial to mid-dermal perivascular and periadnexal lymphocytic infiltrates. Reticular erythematous mucinosis more frequently is reported in women in their 30s and 40s and has been associated with UV exposure and hormonal triggers, such as oral contraceptive medications and pregnancy.⁹

Granuloma annulare typically presents as asymptomatic, erythematous, annular plaques or papules in young women.¹⁰ There are several histologic subtypes that show focal collagen degeneration, inflammation with palisaded or interstitial histiocytes, and mucin deposition, regardless of clinical presentation. Granuloma annulare has been associated with systemic diseases including type 2 diabetes mellitus and thyroid disease. Localized granuloma annulare most commonly presents on the dorsal aspects of the hands or feet.¹⁰

We present a case of LET on the face. Although histologically similar to other dermatoses, LET often lacks epidermal involvement and presents on sun-exposed areas of the body. Jessner lymphocytic infiltration of the skin also should be considered in the differential, as there is an overlap of clinical and histopathological features; JLIS lacks mucin deposits.⁶ This case reinforces the importance of correlating clinical with histopathologic findings. Our patient was treated with tacrolimus ointment 0.1%, and the plaque eventually resolved in 2 to 3 months without recurrence. This condition should be included in the differential diagnosis of recurring annular plaques on sunexposed areas, particularly in middle-aged adults, even in the absence of systemic involvement.

Normal blood pressure (BP) is defined as systolic BP (SBP) < 120 mm Hg and diastolic BP (DBP) < 80 mm Hg.¹ The thresholds for hypertension (HTN) are shown in TABLE 1.¹ These thresholds must be met on at least 2 separate occasions to merit a diagnosis of HTN.¹

Given the high prevalence of HTN and its associated comorbidities, the US Preventive Services Task Force (USPSTF) recently reaffirmed its recommendation that every adult be screened for HTN, regardless of risk factors.² Patients 40 years of age and older and those with risk factors (obesity, family history of HTN, diabetes) should have their BP checked at least annually. Individuals ages 18 to 39 years without risk factors who are initially normotensive should be rescreened within 3 to 5 years.²

Patients are most commonly screened for HTN in the outpatient setting. However, office BP measurements may be inaccurate and are of limited diagnostic utility when taken as a single reading.^1,3,4 As will be described later, office BP measurements are subject to multiple sources of error that can result in a mean underestimation of 24  mm Hg to a mean overestimation of 33 mm Hg for SBP, and a mean underestimation of 14  mm Hg to a mean overestimation of 23 mm Hg for DBP.⁴

Differences to this degree between true BP and measured BP can have important implications for the diagnosis, surveillance, and management of HTN. To diminish this potential for error, the American Heart Association HTN guideline and USPSTF recommendation advise clinicians to obtain out-of-office BP measurements to confirm a diagnosis of HTN before initiating treatment.^1,2 The preferred methods for out-of-office BP assessment are home BP monitoring (HBPM) and 24-hour ambulatory BP monitoring (ABPM).

Limitations of office BP measurement

Multiple sources of error can lead to wide variability in the measurement of office BP, whether taken via the traditional sphygmomanometer auscultatory approach or with an oscillometric monitor.^1,4 Measurement error can be patient related (eg, talking during the reading, or eating or using tobacco prior to measurement), device related (eg, device has not been calibrated or validated), or procedure related (eg, miscuffing, improper patient positioning).

Although use of validated oscillometric monitors eliminates some sources of error such as terminal digit bias, rapid cuff deflation, and missed Korotkoff sounds, their use does not eliminate other sources of error. For example, a patient’s use of tobacco 30 to 60 minutes prior to measurement can raise SBP by 2.8 to 25 mm Hg and DBP 2 to 18 mm Hg.⁴ Having a full bladder can elevate SBP by 4.2 to 33 mm Hg and DBP by 2.8 to 18.5 mm Hg.⁴ If the patient is talking during measurement, is crossing one leg over the opposite knee, or has an unsupported arm below the level of the heart, SBP and DBP can rise, respectively, by an estimated mean 2 to 23 mm Hg and 2 to 14 mm Hg.⁴

Although many sources of BP measurement error can be reduced or eliminated through standardization of technique across office staff, some sources of inaccuracy will persist. Even if all variables are optimized, relying solely on office BP monitoring will still misclassify BP phenotypes, which require out-of-office BP assessments.^1,3FIGURE 1 reviews key tips for maximizing the accuracy of BP measurement, regardless of where the measurement is done.

Continue to: Automated office BP

Automated office BP (AOBP) lessens some of the limitations inherent with the traditional sphygmomanometer auscultatory and single-measurement oscillometric devices. AOBP combines oscillometric technology with the capacity to record multiple BP readings within a single activation, thereby providing an average of these readings.¹ The total time required for AOBP is 4 to 6 minutes, including a brief rest period before the measurement starts. Studies have reported comparable readings between staff-attended and unattended AOBP, which is an encouraging way to eliminate some measurement error (eg, talking with the patient) and to improve efficiency.^5,6

Waiting several minutes per patient to record BP may not be practical in a busy office setting and may require an alteration of workflow. There is a paucity of literature evaluating practice realities, which makes it difficult to know how many patients are getting their BP checked in this manner. Several studies have shown that BP measured with AOBP is closer to awake out-of-office BP as measured with ABPM (discussed in a bit),^5-8 largely through mitigation of white-coat effect. Canada now recommends AOBP as the preferred method for diagnosing HTN and monitoring BP.⁹

Home blood pressure monitoring

HBPM refers to individuals measuring their own BP at home. It is important to remember this definition, as the term is sometimes applied to a patient’s BP measured at home by an observer or to an individual taking their own BP outside of the home (kiosk, pharmacy, at work). The short-term reproducibility of mean BP with HBPM is high. The test-retest correlations of HBPM range from 0.70 to 0.84 mm Hg for mean SBP, and from 0.57 to 0.83 mm Hg for mean DBP.^10-13 In contrast to 24-hour ABPM, HBPM is better tolerated, cheaper, and more widely available.^14,15

There is strong evidence that HBPM adds value over and above office measurements in predicting end-organ damage and cardiovascular disease (CVD) outcomes, and it has a stronger relationship with CVD risk than office BP.¹ Compared with office BP measurement, HBPM is a better predictor of echocardiographic left ventricular mass index, urinary albumin-to-creatinine ratio, proteinuria, silent cerebrovascular disease, nonfatal cardiovascular outcomes, cardiovascular mortality, and all-cause mortality.^15,16 There is no strong evidence demonstrating the superiority of HBPM over ABPM, or vice versa, for predicting CVD events or mortality.¹⁷ Both ABPM and HBPM have important roles in out-of-office monitoring (FIGURE 2³).

Clinical indications for HBPM

HBPM can facilitate diagnosis of white-coat HTN or effect (if already on BP-lowering medication) as well as masked uncontrolled HTN and masked HTN. Importantly, masked HTN is associated with nearly the same risk of target organ damage and cardiovascular events as sustained HTN. In one meta-analysis the overall adjusted hazard ratio for CVD events was 2.00 (95% CI, 1.58-2.52) for masked HTN and 2.28 (95% CI, 1.87-2.78) for sustained HTN, compared with normotensive individuals.¹⁸ Other studies support these results, demonstrating that masked HTN confers risk similar to sustained HTN.^19,20

Even treated subjects with masked uncontrolled HTN (normal office and high home BP) have higher CVD risk, likely due to undertreatment given lower BP in the office setting. Among 1451 treated patients in a large cohort study who were followed for a median of 8.3 years, CVD was higher in those with masked uncontrolled HTN (adjusted hazard ratio = 1.76; 95% CI, 1.23-2.53) compared to treated controlled patients (normal office and home BP).²¹

Home BP monitoring can reveal masked hypertension, which confers risk for endorgan damage similar to that of sustained hypertension.

HBPM also can be used to monitor BP levels over time, to increase patient involvement in chronic disease management, and to improve adherence with medications. Since 2008, several meta-analyses have been published showing improved BP control when HBPM is combined with other interventions and patient education.^22-25 Particularly relevant in the age of increased telehealth, several meta-analyses demonstrate improvement in BP control when HBPM is combined with web- or phone-based support, systematic medication titration, patient education, and provider counseling.^22-25 A comprehensive systematic review found HBPM with this kind of ongoing support (compared with usual care) led to clinic SBP reductions of 3.2 mm Hg (95% CI, 1.6-4.9) at 12 months.²²

Continue to: HBPM nuts and bolts

When using HBPM to obtain a BP average either for confirming a diagnosis or assessing HTN control, patients should be instructed to record their BP measurements twice in the morning and twice at night for a minimum of 3 days (ie, 12 readings).^26,27 For each monitoring period, both SBP and DBP readings should be recorded, although protocols differ as to whether to discard the initial reading of each day, or the entire first day of readings.^26-29 Consecutive days of monitoring are preferred, although nonconsecutive days also are likely to provide valid data. Once BP stabilizes, monitoring 1 to 3 days a week is likely sufficient.

Most guidelines cite a mean BP of ≥ 135/85 mm Hg as the indication of high BP on HBPM.^1,28,29 This value corresponds to an office BP average of 140/90 mm Hg. TABLE 2¹ shows the comparison of home, ambulatory, and office BP thresholds.

Device selection and validation

As with any BP device, validation and proper technique are important. Recommend only upper-arm cuff devices that have passed validation protocols.³⁰ To eliminate the burden on patients to accurately record and store their BP readings, and to eliminate this step as a source of bias, additionally recommend devices with built-in memory. Although easy-to-use wrist and finger monitors have become popular, there are important limitations in terms of accurate positioning and a lack of validated protocols.^31,32

The brachial artery is still the recommended measurement location, unless otherwise precluded due to arm size (the largest size for most validated upper-arm cuffs is 42 cm), patient discomfort, medical contraindication (eg, lymphedema), or immobility (eg, due to injury). Arm size limitation is particularly important as obesity rates continue to rise. Data from the National Health and Nutrition Examination Survey indicate that 52% of men and 38% of women with HTN need a different cuff size than the US standard.³³ If the brachial artery is not an option, there are no definitive data to recommend finger over wrist devices, as both are limited by lack of validated protocols.

The website www.stridebp.org maintains a current list of validated and preferred BP devices, and is supported by the European Society of Hypertension, the International Society of Hypertension, and the World Hypertension League. There are more than 4000 devices on the global market, but only 8% have been validated according to StrideBP.

Advances in HBPM that offset previous limitations

The usefulness of HBPM depends on patient factors such as a commitment to monitoring, applying standardized technique, and accurately recording measurements. Discuss these matters with patients before recommending HBPM. Until recently, HBPM devices could not measure BP during sleep. However, a device that assesses BP during sleep has now come on the US market, with preliminary data suggesting the BP measurements are similar to those obtained with ABPM.³⁴ Advances in device memory and data storage and increased availability of electronic health record connection continue to improve the standardization and reliability of HBPM. In fact, there is a growing list of electronic health portals that can be synced with apps for direct transfer of HBPM data.

Ambulatory blood pressure monitoring

ABPM involves wearing a small device connected to an arm BP cuff that measures BP at pre-programmed intervals over a 24-hour period, during sleep and wakefulness. ABPM is the standard against which HBPM and office BP are compared.^1-3

Continue to: Clinical indications for ABPM

Compared with office-based BP measurements, ABPM has a stronger positive correlation with clinical CVD outcomes and HTN-related organ damage.¹ ABPM has the advantage of being able to provide a large number of measurements over the course of a patient’s daily activities, including sleep. It is useful to evaluate for a wide spectrum of hypertensive or hypotensive patterns, including nocturnal, postprandial, and drug-related patterns. ABPM also is used to assess for white-coat HTN and masked HTN.¹

Among these BP phenotypes, an estimated 15% to 30% of adults in the United States exhibit white-coat HTN.¹ Most evidence suggests that white-coat HTN confers similar cardiovascular risk as normotension, and it therefore does not require treatment.³⁵ Confirming this diagnosis saves the individual and the health care system the cost of unnecessary diagnosis and treatment.

A home monitor that assesses sleep BP is available in some US markets, with data showing its sleep measurements are similar to those obtained with ambulatory BP monitoring.

One cost-effectiveness study using ABPM for annual screening with subsequent treatment for those confirmed to be hypertensive found that ABPM reduced treatment-years by correctly identifying white-coat HTN, and also delayed treatment for those who would eventually develop HTN with advancing age.³⁶ The estimates in savings were 3% to 14% for total cost of care for hypertension and 10% to 23% reduction in treatment days.³⁶ An Australian study showed similar cost reductions.³⁷ A more recent analysis demonstrated that compared with clinic BP measurement alone, incorporation of ABPM is associated with lifetime cost-savings ranging from $77 to $5013, depending on the age and sex of the patients modeled.³⁸

ABPM can also be used to rule out white-coat effect in patients being evaluated for resistant HTN. Several studies demonstrate that among patients with apparent resistant HTN, approximately one-third have controlled BP when assessed by ABPM.^39-41 Thus, it is recommended to conduct an out-of-office BP assessment in patients with apparent resistant HTN prior to adding another medication.⁴¹Twelve percent of US adults have masked HTN.⁴² As described earlier, these patients, unrecognized without out-of-office BP assessment, are twice as likely to experience a CVD event compared with normotensive patients.^1,42,43

ABPM nuts and bolts

ABPM devices are typically worn for 24 hours and with little interruption to daily routines. Prior to BP capture, the device will alert the patient to ensure the patient’s arm can be held still while the BP measurement is being captured.⁴⁴ At the completion of 24 hours, specific software uses the stored data to calculate the BP and heart rate averages, as well as minimums and maximums throughout the monitoring period. Clinical decision-making should be driven by the average BP measurements during times of sleep and wakefulness.^1,14,44FIGURE 3 is an example of output from an ABPM session. TABLE 3^1,44 offers a comparison of HBPM and ABPM.

Limitations of ABPM

While ABPM has been designed to be almost effortless to use, some may find it inconvenient to wear. The repeated cuff inflations can cause discomfort or bruising, and the device can interfere with sleep.⁴⁵ Inconsistent or incorrect wear of ABPM can diminish the quality of BP measurements, which can potentially affect interpretation and subsequent clinical decision-making. Therefore, consider the likelihood of correct and complete usage before ordering ABPM for your patient. Such deliberation is particularly relevant when there is concern for BP phenotypes such as nocturnal nondipping (failure of BP to fall appropriately during sleep) and postprandial HTN and hypotension.

Conduct out-of-office BP assessment of apparent resistant hypertension before adding another medication.

Trained personnel are needed to oversee coordination of the ABPM service within the clinic and to educate patients about proper wear. Additionally, ABPM has not been widely used in US clinical practices to date, in part because this diagnostic strategy is not favorably reimbursed. Based on geographic region, Medicare currently pays between $56 and $122 per 24-hour ABPM session, and only for suspected white-coat HTN.³⁸ Discrepancies remain between commercial and Medicaid/Medicare coverage.⁴⁴

Continue to: Other modes of monitoring BP

Other modes of monitoring BP

The COVID pandemic has changed health care in many ways, including the frequency of in-person visits. As clinics come to rely more on virtual visits and telehealth, accurate monitoring of out-of-office BP has become more important. Kiosks and smart technology offer the opportunity to supplement traditional in-office BP readings. Kiosks are commonly found in pharmacies and grocery stores. These stations facilitate BP monitoring, as long as the device is appropriately validated and calibrated. Unfortunately, most kiosks have only one cuff size that is too small for many US adults, and some do not have a back support.^46,47 Additionally, despite US Food and Drug Administration clearance, many kiosks do not have validated protocols, and the reproducibility of kiosk-measured BP is questionable.^46,47

Mobile health technology is increasingly being examined as an effective means of providing health information, support, and management in chronic disease. Smartphone technology, wearable sensors, and cuffless BP monitors offer promise for providing BP data in more convenient ways. However, as with kiosk devices, very few of these have been validated, and several have been shown to have poor accuracy compared with oscillometric devices.^48-50 For these reasons, kiosk and smart technology for BP monitoring are not recommended at this time, unless no alternatives are available to the patient.

CORRESPONDENCE
Anthony J. Viera, MD, Department of Family Medicine and Community Health, Duke University School of Medicine, 2200 West Main Street, Suite 400, Durham, NC 27705; ajv18@duke.edu

Normal blood pressure (BP) is defined as systolic BP (SBP) < 120 mm Hg and diastolic BP (DBP) < 80 mm Hg.¹ The thresholds for hypertension (HTN) are shown in TABLE 1.¹ These thresholds must be met on at least 2 separate occasions to merit a diagnosis of HTN.¹

Given the high prevalence of HTN and its associated comorbidities, the US Preventive Services Task Force (USPSTF) recently reaffirmed its recommendation that every adult be screened for HTN, regardless of risk factors.² Patients 40 years of age and older and those with risk factors (obesity, family history of HTN, diabetes) should have their BP checked at least annually. Individuals ages 18 to 39 years without risk factors who are initially normotensive should be rescreened within 3 to 5 years.²

Patients are most commonly screened for HTN in the outpatient setting. However, office BP measurements may be inaccurate and are of limited diagnostic utility when taken as a single reading.^1,3,4 As will be described later, office BP measurements are subject to multiple sources of error that can result in a mean underestimation of 24  mm Hg to a mean overestimation of 33 mm Hg for SBP, and a mean underestimation of 14  mm Hg to a mean overestimation of 23 mm Hg for DBP.⁴

Differences to this degree between true BP and measured BP can have important implications for the diagnosis, surveillance, and management of HTN. To diminish this potential for error, the American Heart Association HTN guideline and USPSTF recommendation advise clinicians to obtain out-of-office BP measurements to confirm a diagnosis of HTN before initiating treatment.^1,2 The preferred methods for out-of-office BP assessment are home BP monitoring (HBPM) and 24-hour ambulatory BP monitoring (ABPM).

Limitations of office BP measurement

Multiple sources of error can lead to wide variability in the measurement of office BP, whether taken via the traditional sphygmomanometer auscultatory approach or with an oscillometric monitor.^1,4 Measurement error can be patient related (eg, talking during the reading, or eating or using tobacco prior to measurement), device related (eg, device has not been calibrated or validated), or procedure related (eg, miscuffing, improper patient positioning).

Although use of validated oscillometric monitors eliminates some sources of error such as terminal digit bias, rapid cuff deflation, and missed Korotkoff sounds, their use does not eliminate other sources of error. For example, a patient’s use of tobacco 30 to 60 minutes prior to measurement can raise SBP by 2.8 to 25 mm Hg and DBP 2 to 18 mm Hg.⁴ Having a full bladder can elevate SBP by 4.2 to 33 mm Hg and DBP by 2.8 to 18.5 mm Hg.⁴ If the patient is talking during measurement, is crossing one leg over the opposite knee, or has an unsupported arm below the level of the heart, SBP and DBP can rise, respectively, by an estimated mean 2 to 23 mm Hg and 2 to 14 mm Hg.⁴

Although many sources of BP measurement error can be reduced or eliminated through standardization of technique across office staff, some sources of inaccuracy will persist. Even if all variables are optimized, relying solely on office BP monitoring will still misclassify BP phenotypes, which require out-of-office BP assessments.^1,3FIGURE 1 reviews key tips for maximizing the accuracy of BP measurement, regardless of where the measurement is done.

Continue to: Automated office BP

Automated office BP (AOBP) lessens some of the limitations inherent with the traditional sphygmomanometer auscultatory and single-measurement oscillometric devices. AOBP combines oscillometric technology with the capacity to record multiple BP readings within a single activation, thereby providing an average of these readings.¹ The total time required for AOBP is 4 to 6 minutes, including a brief rest period before the measurement starts. Studies have reported comparable readings between staff-attended and unattended AOBP, which is an encouraging way to eliminate some measurement error (eg, talking with the patient) and to improve efficiency.^5,6

Waiting several minutes per patient to record BP may not be practical in a busy office setting and may require an alteration of workflow. There is a paucity of literature evaluating practice realities, which makes it difficult to know how many patients are getting their BP checked in this manner. Several studies have shown that BP measured with AOBP is closer to awake out-of-office BP as measured with ABPM (discussed in a bit),^5-8 largely through mitigation of white-coat effect. Canada now recommends AOBP as the preferred method for diagnosing HTN and monitoring BP.⁹

Home blood pressure monitoring

HBPM refers to individuals measuring their own BP at home. It is important to remember this definition, as the term is sometimes applied to a patient’s BP measured at home by an observer or to an individual taking their own BP outside of the home (kiosk, pharmacy, at work). The short-term reproducibility of mean BP with HBPM is high. The test-retest correlations of HBPM range from 0.70 to 0.84 mm Hg for mean SBP, and from 0.57 to 0.83 mm Hg for mean DBP.^10-13 In contrast to 24-hour ABPM, HBPM is better tolerated, cheaper, and more widely available.^14,15

There is strong evidence that HBPM adds value over and above office measurements in predicting end-organ damage and cardiovascular disease (CVD) outcomes, and it has a stronger relationship with CVD risk than office BP.¹ Compared with office BP measurement, HBPM is a better predictor of echocardiographic left ventricular mass index, urinary albumin-to-creatinine ratio, proteinuria, silent cerebrovascular disease, nonfatal cardiovascular outcomes, cardiovascular mortality, and all-cause mortality.^15,16 There is no strong evidence demonstrating the superiority of HBPM over ABPM, or vice versa, for predicting CVD events or mortality.¹⁷ Both ABPM and HBPM have important roles in out-of-office monitoring (FIGURE 2³).

Clinical indications for HBPM

HBPM can facilitate diagnosis of white-coat HTN or effect (if already on BP-lowering medication) as well as masked uncontrolled HTN and masked HTN. Importantly, masked HTN is associated with nearly the same risk of target organ damage and cardiovascular events as sustained HTN. In one meta-analysis the overall adjusted hazard ratio for CVD events was 2.00 (95% CI, 1.58-2.52) for masked HTN and 2.28 (95% CI, 1.87-2.78) for sustained HTN, compared with normotensive individuals.¹⁸ Other studies support these results, demonstrating that masked HTN confers risk similar to sustained HTN.^19,20

Even treated subjects with masked uncontrolled HTN (normal office and high home BP) have higher CVD risk, likely due to undertreatment given lower BP in the office setting. Among 1451 treated patients in a large cohort study who were followed for a median of 8.3 years, CVD was higher in those with masked uncontrolled HTN (adjusted hazard ratio = 1.76; 95% CI, 1.23-2.53) compared to treated controlled patients (normal office and home BP).²¹

Home BP monitoring can reveal masked hypertension, which confers risk for endorgan damage similar to that of sustained hypertension.

HBPM also can be used to monitor BP levels over time, to increase patient involvement in chronic disease management, and to improve adherence with medications. Since 2008, several meta-analyses have been published showing improved BP control when HBPM is combined with other interventions and patient education.^22-25 Particularly relevant in the age of increased telehealth, several meta-analyses demonstrate improvement in BP control when HBPM is combined with web- or phone-based support, systematic medication titration, patient education, and provider counseling.^22-25 A comprehensive systematic review found HBPM with this kind of ongoing support (compared with usual care) led to clinic SBP reductions of 3.2 mm Hg (95% CI, 1.6-4.9) at 12 months.²²

Continue to: HBPM nuts and bolts

When using HBPM to obtain a BP average either for confirming a diagnosis or assessing HTN control, patients should be instructed to record their BP measurements twice in the morning and twice at night for a minimum of 3 days (ie, 12 readings).^26,27 For each monitoring period, both SBP and DBP readings should be recorded, although protocols differ as to whether to discard the initial reading of each day, or the entire first day of readings.^26-29 Consecutive days of monitoring are preferred, although nonconsecutive days also are likely to provide valid data. Once BP stabilizes, monitoring 1 to 3 days a week is likely sufficient.

Most guidelines cite a mean BP of ≥ 135/85 mm Hg as the indication of high BP on HBPM.^1,28,29 This value corresponds to an office BP average of 140/90 mm Hg. TABLE 2¹ shows the comparison of home, ambulatory, and office BP thresholds.

Device selection and validation

As with any BP device, validation and proper technique are important. Recommend only upper-arm cuff devices that have passed validation protocols.³⁰ To eliminate the burden on patients to accurately record and store their BP readings, and to eliminate this step as a source of bias, additionally recommend devices with built-in memory. Although easy-to-use wrist and finger monitors have become popular, there are important limitations in terms of accurate positioning and a lack of validated protocols.^31,32

The brachial artery is still the recommended measurement location, unless otherwise precluded due to arm size (the largest size for most validated upper-arm cuffs is 42 cm), patient discomfort, medical contraindication (eg, lymphedema), or immobility (eg, due to injury). Arm size limitation is particularly important as obesity rates continue to rise. Data from the National Health and Nutrition Examination Survey indicate that 52% of men and 38% of women with HTN need a different cuff size than the US standard.³³ If the brachial artery is not an option, there are no definitive data to recommend finger over wrist devices, as both are limited by lack of validated protocols.

The website www.stridebp.org maintains a current list of validated and preferred BP devices, and is supported by the European Society of Hypertension, the International Society of Hypertension, and the World Hypertension League. There are more than 4000 devices on the global market, but only 8% have been validated according to StrideBP.

Advances in HBPM that offset previous limitations

The usefulness of HBPM depends on patient factors such as a commitment to monitoring, applying standardized technique, and accurately recording measurements. Discuss these matters with patients before recommending HBPM. Until recently, HBPM devices could not measure BP during sleep. However, a device that assesses BP during sleep has now come on the US market, with preliminary data suggesting the BP measurements are similar to those obtained with ABPM.³⁴ Advances in device memory and data storage and increased availability of electronic health record connection continue to improve the standardization and reliability of HBPM. In fact, there is a growing list of electronic health portals that can be synced with apps for direct transfer of HBPM data.

Ambulatory blood pressure monitoring

ABPM involves wearing a small device connected to an arm BP cuff that measures BP at pre-programmed intervals over a 24-hour period, during sleep and wakefulness. ABPM is the standard against which HBPM and office BP are compared.^1-3

Continue to: Clinical indications for ABPM

Compared with office-based BP measurements, ABPM has a stronger positive correlation with clinical CVD outcomes and HTN-related organ damage.¹ ABPM has the advantage of being able to provide a large number of measurements over the course of a patient’s daily activities, including sleep. It is useful to evaluate for a wide spectrum of hypertensive or hypotensive patterns, including nocturnal, postprandial, and drug-related patterns. ABPM also is used to assess for white-coat HTN and masked HTN.¹

Among these BP phenotypes, an estimated 15% to 30% of adults in the United States exhibit white-coat HTN.¹ Most evidence suggests that white-coat HTN confers similar cardiovascular risk as normotension, and it therefore does not require treatment.³⁵ Confirming this diagnosis saves the individual and the health care system the cost of unnecessary diagnosis and treatment.

A home monitor that assesses sleep BP is available in some US markets, with data showing its sleep measurements are similar to those obtained with ambulatory BP monitoring.

One cost-effectiveness study using ABPM for annual screening with subsequent treatment for those confirmed to be hypertensive found that ABPM reduced treatment-years by correctly identifying white-coat HTN, and also delayed treatment for those who would eventually develop HTN with advancing age.³⁶ The estimates in savings were 3% to 14% for total cost of care for hypertension and 10% to 23% reduction in treatment days.³⁶ An Australian study showed similar cost reductions.³⁷ A more recent analysis demonstrated that compared with clinic BP measurement alone, incorporation of ABPM is associated with lifetime cost-savings ranging from $77 to $5013, depending on the age and sex of the patients modeled.³⁸

ABPM can also be used to rule out white-coat effect in patients being evaluated for resistant HTN. Several studies demonstrate that among patients with apparent resistant HTN, approximately one-third have controlled BP when assessed by ABPM.^39-41 Thus, it is recommended to conduct an out-of-office BP assessment in patients with apparent resistant HTN prior to adding another medication.⁴¹Twelve percent of US adults have masked HTN.⁴² As described earlier, these patients, unrecognized without out-of-office BP assessment, are twice as likely to experience a CVD event compared with normotensive patients.^1,42,43

ABPM nuts and bolts

ABPM devices are typically worn for 24 hours and with little interruption to daily routines. Prior to BP capture, the device will alert the patient to ensure the patient’s arm can be held still while the BP measurement is being captured.⁴⁴ At the completion of 24 hours, specific software uses the stored data to calculate the BP and heart rate averages, as well as minimums and maximums throughout the monitoring period. Clinical decision-making should be driven by the average BP measurements during times of sleep and wakefulness.^1,14,44FIGURE 3 is an example of output from an ABPM session. TABLE 3^1,44 offers a comparison of HBPM and ABPM.

Limitations of ABPM

While ABPM has been designed to be almost effortless to use, some may find it inconvenient to wear. The repeated cuff inflations can cause discomfort or bruising, and the device can interfere with sleep.⁴⁵ Inconsistent or incorrect wear of ABPM can diminish the quality of BP measurements, which can potentially affect interpretation and subsequent clinical decision-making. Therefore, consider the likelihood of correct and complete usage before ordering ABPM for your patient. Such deliberation is particularly relevant when there is concern for BP phenotypes such as nocturnal nondipping (failure of BP to fall appropriately during sleep) and postprandial HTN and hypotension.

Conduct out-of-office BP assessment of apparent resistant hypertension before adding another medication.

Trained personnel are needed to oversee coordination of the ABPM service within the clinic and to educate patients about proper wear. Additionally, ABPM has not been widely used in US clinical practices to date, in part because this diagnostic strategy is not favorably reimbursed. Based on geographic region, Medicare currently pays between $56 and $122 per 24-hour ABPM session, and only for suspected white-coat HTN.³⁸ Discrepancies remain between commercial and Medicaid/Medicare coverage.⁴⁴

Continue to: Other modes of monitoring BP

Other modes of monitoring BP

The COVID pandemic has changed health care in many ways, including the frequency of in-person visits. As clinics come to rely more on virtual visits and telehealth, accurate monitoring of out-of-office BP has become more important. Kiosks and smart technology offer the opportunity to supplement traditional in-office BP readings. Kiosks are commonly found in pharmacies and grocery stores. These stations facilitate BP monitoring, as long as the device is appropriately validated and calibrated. Unfortunately, most kiosks have only one cuff size that is too small for many US adults, and some do not have a back support.^46,47 Additionally, despite US Food and Drug Administration clearance, many kiosks do not have validated protocols, and the reproducibility of kiosk-measured BP is questionable.^46,47

Mobile health technology is increasingly being examined as an effective means of providing health information, support, and management in chronic disease. Smartphone technology, wearable sensors, and cuffless BP monitors offer promise for providing BP data in more convenient ways. However, as with kiosk devices, very few of these have been validated, and several have been shown to have poor accuracy compared with oscillometric devices.^48-50 For these reasons, kiosk and smart technology for BP monitoring are not recommended at this time, unless no alternatives are available to the patient.

CORRESPONDENCE
Anthony J. Viera, MD, Department of Family Medicine and Community Health, Duke University School of Medicine, 2200 West Main Street, Suite 400, Durham, NC 27705; ajv18@duke.edu

Normal blood pressure (BP) is defined as systolic BP (SBP) < 120 mm Hg and diastolic BP (DBP) < 80 mm Hg.¹ The thresholds for hypertension (HTN) are shown in TABLE 1.¹ These thresholds must be met on at least 2 separate occasions to merit a diagnosis of HTN.¹

Given the high prevalence of HTN and its associated comorbidities, the US Preventive Services Task Force (USPSTF) recently reaffirmed its recommendation that every adult be screened for HTN, regardless of risk factors.² Patients 40 years of age and older and those with risk factors (obesity, family history of HTN, diabetes) should have their BP checked at least annually. Individuals ages 18 to 39 years without risk factors who are initially normotensive should be rescreened within 3 to 5 years.²

Patients are most commonly screened for HTN in the outpatient setting. However, office BP measurements may be inaccurate and are of limited diagnostic utility when taken as a single reading.^1,3,4 As will be described later, office BP measurements are subject to multiple sources of error that can result in a mean underestimation of 24  mm Hg to a mean overestimation of 33 mm Hg for SBP, and a mean underestimation of 14  mm Hg to a mean overestimation of 23 mm Hg for DBP.⁴

Differences to this degree between true BP and measured BP can have important implications for the diagnosis, surveillance, and management of HTN. To diminish this potential for error, the American Heart Association HTN guideline and USPSTF recommendation advise clinicians to obtain out-of-office BP measurements to confirm a diagnosis of HTN before initiating treatment.^1,2 The preferred methods for out-of-office BP assessment are home BP monitoring (HBPM) and 24-hour ambulatory BP monitoring (ABPM).

Limitations of office BP measurement

Multiple sources of error can lead to wide variability in the measurement of office BP, whether taken via the traditional sphygmomanometer auscultatory approach or with an oscillometric monitor.^1,4 Measurement error can be patient related (eg, talking during the reading, or eating or using tobacco prior to measurement), device related (eg, device has not been calibrated or validated), or procedure related (eg, miscuffing, improper patient positioning).

Although use of validated oscillometric monitors eliminates some sources of error such as terminal digit bias, rapid cuff deflation, and missed Korotkoff sounds, their use does not eliminate other sources of error. For example, a patient’s use of tobacco 30 to 60 minutes prior to measurement can raise SBP by 2.8 to 25 mm Hg and DBP 2 to 18 mm Hg.⁴ Having a full bladder can elevate SBP by 4.2 to 33 mm Hg and DBP by 2.8 to 18.5 mm Hg.⁴ If the patient is talking during measurement, is crossing one leg over the opposite knee, or has an unsupported arm below the level of the heart, SBP and DBP can rise, respectively, by an estimated mean 2 to 23 mm Hg and 2 to 14 mm Hg.⁴

Although many sources of BP measurement error can be reduced or eliminated through standardization of technique across office staff, some sources of inaccuracy will persist. Even if all variables are optimized, relying solely on office BP monitoring will still misclassify BP phenotypes, which require out-of-office BP assessments.^1,3FIGURE 1 reviews key tips for maximizing the accuracy of BP measurement, regardless of where the measurement is done.

Continue to: Automated office BP

Automated office BP (AOBP) lessens some of the limitations inherent with the traditional sphygmomanometer auscultatory and single-measurement oscillometric devices. AOBP combines oscillometric technology with the capacity to record multiple BP readings within a single activation, thereby providing an average of these readings.¹ The total time required for AOBP is 4 to 6 minutes, including a brief rest period before the measurement starts. Studies have reported comparable readings between staff-attended and unattended AOBP, which is an encouraging way to eliminate some measurement error (eg, talking with the patient) and to improve efficiency.^5,6

Waiting several minutes per patient to record BP may not be practical in a busy office setting and may require an alteration of workflow. There is a paucity of literature evaluating practice realities, which makes it difficult to know how many patients are getting their BP checked in this manner. Several studies have shown that BP measured with AOBP is closer to awake out-of-office BP as measured with ABPM (discussed in a bit),^5-8 largely through mitigation of white-coat effect. Canada now recommends AOBP as the preferred method for diagnosing HTN and monitoring BP.⁹

Home blood pressure monitoring

HBPM refers to individuals measuring their own BP at home. It is important to remember this definition, as the term is sometimes applied to a patient’s BP measured at home by an observer or to an individual taking their own BP outside of the home (kiosk, pharmacy, at work). The short-term reproducibility of mean BP with HBPM is high. The test-retest correlations of HBPM range from 0.70 to 0.84 mm Hg for mean SBP, and from 0.57 to 0.83 mm Hg for mean DBP.^10-13 In contrast to 24-hour ABPM, HBPM is better tolerated, cheaper, and more widely available.^14,15

There is strong evidence that HBPM adds value over and above office measurements in predicting end-organ damage and cardiovascular disease (CVD) outcomes, and it has a stronger relationship with CVD risk than office BP.¹ Compared with office BP measurement, HBPM is a better predictor of echocardiographic left ventricular mass index, urinary albumin-to-creatinine ratio, proteinuria, silent cerebrovascular disease, nonfatal cardiovascular outcomes, cardiovascular mortality, and all-cause mortality.^15,16 There is no strong evidence demonstrating the superiority of HBPM over ABPM, or vice versa, for predicting CVD events or mortality.¹⁷ Both ABPM and HBPM have important roles in out-of-office monitoring (FIGURE 2³).

Clinical indications for HBPM

HBPM can facilitate diagnosis of white-coat HTN or effect (if already on BP-lowering medication) as well as masked uncontrolled HTN and masked HTN. Importantly, masked HTN is associated with nearly the same risk of target organ damage and cardiovascular events as sustained HTN. In one meta-analysis the overall adjusted hazard ratio for CVD events was 2.00 (95% CI, 1.58-2.52) for masked HTN and 2.28 (95% CI, 1.87-2.78) for sustained HTN, compared with normotensive individuals.¹⁸ Other studies support these results, demonstrating that masked HTN confers risk similar to sustained HTN.^19,20

Even treated subjects with masked uncontrolled HTN (normal office and high home BP) have higher CVD risk, likely due to undertreatment given lower BP in the office setting. Among 1451 treated patients in a large cohort study who were followed for a median of 8.3 years, CVD was higher in those with masked uncontrolled HTN (adjusted hazard ratio = 1.76; 95% CI, 1.23-2.53) compared to treated controlled patients (normal office and home BP).²¹

Home BP monitoring can reveal masked hypertension, which confers risk for endorgan damage similar to that of sustained hypertension.

HBPM also can be used to monitor BP levels over time, to increase patient involvement in chronic disease management, and to improve adherence with medications. Since 2008, several meta-analyses have been published showing improved BP control when HBPM is combined with other interventions and patient education.^22-25 Particularly relevant in the age of increased telehealth, several meta-analyses demonstrate improvement in BP control when HBPM is combined with web- or phone-based support, systematic medication titration, patient education, and provider counseling.^22-25 A comprehensive systematic review found HBPM with this kind of ongoing support (compared with usual care) led to clinic SBP reductions of 3.2 mm Hg (95% CI, 1.6-4.9) at 12 months.²²

Continue to: HBPM nuts and bolts

When using HBPM to obtain a BP average either for confirming a diagnosis or assessing HTN control, patients should be instructed to record their BP measurements twice in the morning and twice at night for a minimum of 3 days (ie, 12 readings).^26,27 For each monitoring period, both SBP and DBP readings should be recorded, although protocols differ as to whether to discard the initial reading of each day, or the entire first day of readings.^26-29 Consecutive days of monitoring are preferred, although nonconsecutive days also are likely to provide valid data. Once BP stabilizes, monitoring 1 to 3 days a week is likely sufficient.

Most guidelines cite a mean BP of ≥ 135/85 mm Hg as the indication of high BP on HBPM.^1,28,29 This value corresponds to an office BP average of 140/90 mm Hg. TABLE 2¹ shows the comparison of home, ambulatory, and office BP thresholds.

Device selection and validation

As with any BP device, validation and proper technique are important. Recommend only upper-arm cuff devices that have passed validation protocols.³⁰ To eliminate the burden on patients to accurately record and store their BP readings, and to eliminate this step as a source of bias, additionally recommend devices with built-in memory. Although easy-to-use wrist and finger monitors have become popular, there are important limitations in terms of accurate positioning and a lack of validated protocols.^31,32

The brachial artery is still the recommended measurement location, unless otherwise precluded due to arm size (the largest size for most validated upper-arm cuffs is 42 cm), patient discomfort, medical contraindication (eg, lymphedema), or immobility (eg, due to injury). Arm size limitation is particularly important as obesity rates continue to rise. Data from the National Health and Nutrition Examination Survey indicate that 52% of men and 38% of women with HTN need a different cuff size than the US standard.³³ If the brachial artery is not an option, there are no definitive data to recommend finger over wrist devices, as both are limited by lack of validated protocols.

The website www.stridebp.org maintains a current list of validated and preferred BP devices, and is supported by the European Society of Hypertension, the International Society of Hypertension, and the World Hypertension League. There are more than 4000 devices on the global market, but only 8% have been validated according to StrideBP.

Advances in HBPM that offset previous limitations

The usefulness of HBPM depends on patient factors such as a commitment to monitoring, applying standardized technique, and accurately recording measurements. Discuss these matters with patients before recommending HBPM. Until recently, HBPM devices could not measure BP during sleep. However, a device that assesses BP during sleep has now come on the US market, with preliminary data suggesting the BP measurements are similar to those obtained with ABPM.³⁴ Advances in device memory and data storage and increased availability of electronic health record connection continue to improve the standardization and reliability of HBPM. In fact, there is a growing list of electronic health portals that can be synced with apps for direct transfer of HBPM data.

Ambulatory blood pressure monitoring

ABPM involves wearing a small device connected to an arm BP cuff that measures BP at pre-programmed intervals over a 24-hour period, during sleep and wakefulness. ABPM is the standard against which HBPM and office BP are compared.^1-3

Continue to: Clinical indications for ABPM

Compared with office-based BP measurements, ABPM has a stronger positive correlation with clinical CVD outcomes and HTN-related organ damage.¹ ABPM has the advantage of being able to provide a large number of measurements over the course of a patient’s daily activities, including sleep. It is useful to evaluate for a wide spectrum of hypertensive or hypotensive patterns, including nocturnal, postprandial, and drug-related patterns. ABPM also is used to assess for white-coat HTN and masked HTN.¹

Among these BP phenotypes, an estimated 15% to 30% of adults in the United States exhibit white-coat HTN.¹ Most evidence suggests that white-coat HTN confers similar cardiovascular risk as normotension, and it therefore does not require treatment.³⁵ Confirming this diagnosis saves the individual and the health care system the cost of unnecessary diagnosis and treatment.

A home monitor that assesses sleep BP is available in some US markets, with data showing its sleep measurements are similar to those obtained with ambulatory BP monitoring.

One cost-effectiveness study using ABPM for annual screening with subsequent treatment for those confirmed to be hypertensive found that ABPM reduced treatment-years by correctly identifying white-coat HTN, and also delayed treatment for those who would eventually develop HTN with advancing age.³⁶ The estimates in savings were 3% to 14% for total cost of care for hypertension and 10% to 23% reduction in treatment days.³⁶ An Australian study showed similar cost reductions.³⁷ A more recent analysis demonstrated that compared with clinic BP measurement alone, incorporation of ABPM is associated with lifetime cost-savings ranging from $77 to $5013, depending on the age and sex of the patients modeled.³⁸

ABPM can also be used to rule out white-coat effect in patients being evaluated for resistant HTN. Several studies demonstrate that among patients with apparent resistant HTN, approximately one-third have controlled BP when assessed by ABPM.^39-41 Thus, it is recommended to conduct an out-of-office BP assessment in patients with apparent resistant HTN prior to adding another medication.⁴¹Twelve percent of US adults have masked HTN.⁴² As described earlier, these patients, unrecognized without out-of-office BP assessment, are twice as likely to experience a CVD event compared with normotensive patients.^1,42,43

ABPM nuts and bolts

ABPM devices are typically worn for 24 hours and with little interruption to daily routines. Prior to BP capture, the device will alert the patient to ensure the patient’s arm can be held still while the BP measurement is being captured.⁴⁴ At the completion of 24 hours, specific software uses the stored data to calculate the BP and heart rate averages, as well as minimums and maximums throughout the monitoring period. Clinical decision-making should be driven by the average BP measurements during times of sleep and wakefulness.^1,14,44FIGURE 3 is an example of output from an ABPM session. TABLE 3^1,44 offers a comparison of HBPM and ABPM.

Limitations of ABPM

While ABPM has been designed to be almost effortless to use, some may find it inconvenient to wear. The repeated cuff inflations can cause discomfort or bruising, and the device can interfere with sleep.⁴⁵ Inconsistent or incorrect wear of ABPM can diminish the quality of BP measurements, which can potentially affect interpretation and subsequent clinical decision-making. Therefore, consider the likelihood of correct and complete usage before ordering ABPM for your patient. Such deliberation is particularly relevant when there is concern for BP phenotypes such as nocturnal nondipping (failure of BP to fall appropriately during sleep) and postprandial HTN and hypotension.

Conduct out-of-office BP assessment of apparent resistant hypertension before adding another medication.

Trained personnel are needed to oversee coordination of the ABPM service within the clinic and to educate patients about proper wear. Additionally, ABPM has not been widely used in US clinical practices to date, in part because this diagnostic strategy is not favorably reimbursed. Based on geographic region, Medicare currently pays between $56 and $122 per 24-hour ABPM session, and only for suspected white-coat HTN.³⁸ Discrepancies remain between commercial and Medicaid/Medicare coverage.⁴⁴

Continue to: Other modes of monitoring BP

Other modes of monitoring BP

The COVID pandemic has changed health care in many ways, including the frequency of in-person visits. As clinics come to rely more on virtual visits and telehealth, accurate monitoring of out-of-office BP has become more important. Kiosks and smart technology offer the opportunity to supplement traditional in-office BP readings. Kiosks are commonly found in pharmacies and grocery stores. These stations facilitate BP monitoring, as long as the device is appropriately validated and calibrated. Unfortunately, most kiosks have only one cuff size that is too small for many US adults, and some do not have a back support.^46,47 Additionally, despite US Food and Drug Administration clearance, many kiosks do not have validated protocols, and the reproducibility of kiosk-measured BP is questionable.^46,47

Mobile health technology is increasingly being examined as an effective means of providing health information, support, and management in chronic disease. Smartphone technology, wearable sensors, and cuffless BP monitors offer promise for providing BP data in more convenient ways. However, as with kiosk devices, very few of these have been validated, and several have been shown to have poor accuracy compared with oscillometric devices.^48-50 For these reasons, kiosk and smart technology for BP monitoring are not recommended at this time, unless no alternatives are available to the patient.

CORRESPONDENCE
Anthony J. Viera, MD, Department of Family Medicine and Community Health, Duke University School of Medicine, 2200 West Main Street, Suite 400, Durham, NC 27705; ajv18@duke.edu

The Diagnosis: Calciphylaxis

Histopathology revealed epidermal and dermal necrosis, a perivascular neutrophilic infiltrate, and scattered microcalcifications within small- and medium-sized subcutaneous vessels, consistent with a diagnosis of calciphylaxis (Figure). Calciphylaxis (also known as calcific uremic arteriolopathy) is a rare, severe, and often fatal vasculopathy that predominately occurs in patients with end-stage renal failure.¹ The pathogenesis of calciphylaxis remains poorly understood; however, it generally is thought that an imbalance in calcium homeostasis in susceptible hosts results in the precipitation of calcium phosphate within vessel walls leading to endothelial damage with subsequent thrombotic vasculopathy and ischemic tissue damage. Acquired and congenital hypercoagulable states have been implicated in the pathogenesis of calciphylaxis.²

Treatment of calciphylaxis is directed at normalizing abnormal calcium metabolism; removing possible exacerbating agents, such as warfarin, systemic corticosteroids, calcium, and iron; and transitioning patients with end-stage renal disease to hemodialysis, if not already initiated. The treatment approach is multifaceted, and numerous therapies usually are attempted simultaneously. Vitamin K supplementation, low-calcium dialysate, non–calcium carbonate phosphate binders, cinacalcet, becaplermin, bisphosphonates, hyperbaric oxygen, and intravenous sodium thiosulfate all have been utilized with some success. Currently, intravenous sodium thiosulfate is the mainstay therapy for the treatment of calciphylaxis.² Although the mechanism of sodium thiosulfate is not entirely understood, it is known to have anticalcification, vasodilatory, and antioxidant properties.

Retiform purpura clinically is characterized by reticulated, branching, purpuric skin lesions. It occurs following vascular insult by way of vessel lumen occlusion (thrombotic vasculopathy) and less frequently by vessel wall inflammation (vasculitis). The differential diagnosis for retiform purpura includes various causes of microvascular occlusion, including hypercoagulable states and type I cryoglobulinemia, calciphylaxis, infections, autoimmune vasculitic conditions, and embolic causes.³

Cutaneous disease in individuals with antiphospholipid antibodies may present similarly with retiform purpura in the form of necrotizing livedo reticularis, leg ulcers, or widespread cutaneous necrosis. Histopathologic findings include vascular thrombi with partial or complete obstruction of the small- to medium-sized arteries at the dermoepidermal junction, often in the absence of an inflammatory infiltrate.⁴ True vasculitis is not typical of antiphospholipid syndrome.

Medium vessel vasculitides, such as polyarteritis nodosa, clinically present with livedo reticularis, subcutaneous nodules, and tissue necrosis. Dermatopathologic evaluation of a medium-sized vessel vasculitis would demonstrate a neutrophilic vasculitis involving vessels within the deep dermis and septa of subcutaneous fat.⁵ Tissue sampling should be deep and wide enough to visualize the pathology, as shallow biopsies may show intraluminal thrombi of the superficial dermal plexus only, while a narrow specimen may result in falsenegative findings due to the focal nature of vessel involvement in conditions such as polyarteritis nodosa.

Type I cryoglobulinemia often is a manifestation of plasma cell dyscrasia and commonly presents with Raynaud phenomenon, livedo reticularis, and acrocyanosis of helices⁶ ; pathology demonstrates vessel occlusion and erythrocyte extravasation. In contrast, types II and III, also known as mixed cryoglobulinemia, are associated with hepatitis C and autoimmune connective tissue disease. They clinically present as purpuric plaques and nodules that have a propensity to vesiculate and ulcerate.⁷ Histopathologically, features of leukocytoclastic vasculitis are seen, and direct immunofluorescence demonstrates perivascular granular deposits consisting predominantly of IgM and C3 in the papillary dermis.⁸

Warfarin therapy, particularly in high initial doses, can induce lesions of cutaneous necrosis, which clinically may resemble the appearance of calciphylaxis. Warfarininduced skin necrosis typically occurs 3 to 5 days after the initiation of therapy and is the result of a temporary prothrombotic state.9 The half-life of antithrombotic protein C is shorter than vitamin K–dependent prothrombotic factors II, X, and IX. Early in warfarin treatment, an acquired state of reduced protein C level exists, which can lead to vessel thrombosis and subsequent cutaneous necrosis. Treatment of warfarin-induced skin necrosis involves cessation of warfarin, supplementation with vitamin K to reverse the effects of warfarin, and the initiation of heparin or low-molecular-weight heparin.⁹

The Diagnosis: Calciphylaxis

Histopathology revealed epidermal and dermal necrosis, a perivascular neutrophilic infiltrate, and scattered microcalcifications within small- and medium-sized subcutaneous vessels, consistent with a diagnosis of calciphylaxis (Figure). Calciphylaxis (also known as calcific uremic arteriolopathy) is a rare, severe, and often fatal vasculopathy that predominately occurs in patients with end-stage renal failure.¹ The pathogenesis of calciphylaxis remains poorly understood; however, it generally is thought that an imbalance in calcium homeostasis in susceptible hosts results in the precipitation of calcium phosphate within vessel walls leading to endothelial damage with subsequent thrombotic vasculopathy and ischemic tissue damage. Acquired and congenital hypercoagulable states have been implicated in the pathogenesis of calciphylaxis.²

Treatment of calciphylaxis is directed at normalizing abnormal calcium metabolism; removing possible exacerbating agents, such as warfarin, systemic corticosteroids, calcium, and iron; and transitioning patients with end-stage renal disease to hemodialysis, if not already initiated. The treatment approach is multifaceted, and numerous therapies usually are attempted simultaneously. Vitamin K supplementation, low-calcium dialysate, non–calcium carbonate phosphate binders, cinacalcet, becaplermin, bisphosphonates, hyperbaric oxygen, and intravenous sodium thiosulfate all have been utilized with some success. Currently, intravenous sodium thiosulfate is the mainstay therapy for the treatment of calciphylaxis.² Although the mechanism of sodium thiosulfate is not entirely understood, it is known to have anticalcification, vasodilatory, and antioxidant properties.

Retiform purpura clinically is characterized by reticulated, branching, purpuric skin lesions. It occurs following vascular insult by way of vessel lumen occlusion (thrombotic vasculopathy) and less frequently by vessel wall inflammation (vasculitis). The differential diagnosis for retiform purpura includes various causes of microvascular occlusion, including hypercoagulable states and type I cryoglobulinemia, calciphylaxis, infections, autoimmune vasculitic conditions, and embolic causes.³

Cutaneous disease in individuals with antiphospholipid antibodies may present similarly with retiform purpura in the form of necrotizing livedo reticularis, leg ulcers, or widespread cutaneous necrosis. Histopathologic findings include vascular thrombi with partial or complete obstruction of the small- to medium-sized arteries at the dermoepidermal junction, often in the absence of an inflammatory infiltrate.⁴ True vasculitis is not typical of antiphospholipid syndrome.

Medium vessel vasculitides, such as polyarteritis nodosa, clinically present with livedo reticularis, subcutaneous nodules, and tissue necrosis. Dermatopathologic evaluation of a medium-sized vessel vasculitis would demonstrate a neutrophilic vasculitis involving vessels within the deep dermis and septa of subcutaneous fat.⁵ Tissue sampling should be deep and wide enough to visualize the pathology, as shallow biopsies may show intraluminal thrombi of the superficial dermal plexus only, while a narrow specimen may result in falsenegative findings due to the focal nature of vessel involvement in conditions such as polyarteritis nodosa.

Type I cryoglobulinemia often is a manifestation of plasma cell dyscrasia and commonly presents with Raynaud phenomenon, livedo reticularis, and acrocyanosis of helices⁶ ; pathology demonstrates vessel occlusion and erythrocyte extravasation. In contrast, types II and III, also known as mixed cryoglobulinemia, are associated with hepatitis C and autoimmune connective tissue disease. They clinically present as purpuric plaques and nodules that have a propensity to vesiculate and ulcerate.⁷ Histopathologically, features of leukocytoclastic vasculitis are seen, and direct immunofluorescence demonstrates perivascular granular deposits consisting predominantly of IgM and C3 in the papillary dermis.⁸

Warfarin therapy, particularly in high initial doses, can induce lesions of cutaneous necrosis, which clinically may resemble the appearance of calciphylaxis. Warfarininduced skin necrosis typically occurs 3 to 5 days after the initiation of therapy and is the result of a temporary prothrombotic state.9 The half-life of antithrombotic protein C is shorter than vitamin K–dependent prothrombotic factors II, X, and IX. Early in warfarin treatment, an acquired state of reduced protein C level exists, which can lead to vessel thrombosis and subsequent cutaneous necrosis. Treatment of warfarin-induced skin necrosis involves cessation of warfarin, supplementation with vitamin K to reverse the effects of warfarin, and the initiation of heparin or low-molecular-weight heparin.⁹

The Diagnosis: Calciphylaxis

Histopathology revealed epidermal and dermal necrosis, a perivascular neutrophilic infiltrate, and scattered microcalcifications within small- and medium-sized subcutaneous vessels, consistent with a diagnosis of calciphylaxis (Figure). Calciphylaxis (also known as calcific uremic arteriolopathy) is a rare, severe, and often fatal vasculopathy that predominately occurs in patients with end-stage renal failure.¹ The pathogenesis of calciphylaxis remains poorly understood; however, it generally is thought that an imbalance in calcium homeostasis in susceptible hosts results in the precipitation of calcium phosphate within vessel walls leading to endothelial damage with subsequent thrombotic vasculopathy and ischemic tissue damage. Acquired and congenital hypercoagulable states have been implicated in the pathogenesis of calciphylaxis.²

Treatment of calciphylaxis is directed at normalizing abnormal calcium metabolism; removing possible exacerbating agents, such as warfarin, systemic corticosteroids, calcium, and iron; and transitioning patients with end-stage renal disease to hemodialysis, if not already initiated. The treatment approach is multifaceted, and numerous therapies usually are attempted simultaneously. Vitamin K supplementation, low-calcium dialysate, non–calcium carbonate phosphate binders, cinacalcet, becaplermin, bisphosphonates, hyperbaric oxygen, and intravenous sodium thiosulfate all have been utilized with some success. Currently, intravenous sodium thiosulfate is the mainstay therapy for the treatment of calciphylaxis.² Although the mechanism of sodium thiosulfate is not entirely understood, it is known to have anticalcification, vasodilatory, and antioxidant properties.

Retiform purpura clinically is characterized by reticulated, branching, purpuric skin lesions. It occurs following vascular insult by way of vessel lumen occlusion (thrombotic vasculopathy) and less frequently by vessel wall inflammation (vasculitis). The differential diagnosis for retiform purpura includes various causes of microvascular occlusion, including hypercoagulable states and type I cryoglobulinemia, calciphylaxis, infections, autoimmune vasculitic conditions, and embolic causes.³

Cutaneous disease in individuals with antiphospholipid antibodies may present similarly with retiform purpura in the form of necrotizing livedo reticularis, leg ulcers, or widespread cutaneous necrosis. Histopathologic findings include vascular thrombi with partial or complete obstruction of the small- to medium-sized arteries at the dermoepidermal junction, often in the absence of an inflammatory infiltrate.⁴ True vasculitis is not typical of antiphospholipid syndrome.

Medium vessel vasculitides, such as polyarteritis nodosa, clinically present with livedo reticularis, subcutaneous nodules, and tissue necrosis. Dermatopathologic evaluation of a medium-sized vessel vasculitis would demonstrate a neutrophilic vasculitis involving vessels within the deep dermis and septa of subcutaneous fat.⁵ Tissue sampling should be deep and wide enough to visualize the pathology, as shallow biopsies may show intraluminal thrombi of the superficial dermal plexus only, while a narrow specimen may result in falsenegative findings due to the focal nature of vessel involvement in conditions such as polyarteritis nodosa.

Type I cryoglobulinemia often is a manifestation of plasma cell dyscrasia and commonly presents with Raynaud phenomenon, livedo reticularis, and acrocyanosis of helices⁶ ; pathology demonstrates vessel occlusion and erythrocyte extravasation. In contrast, types II and III, also known as mixed cryoglobulinemia, are associated with hepatitis C and autoimmune connective tissue disease. They clinically present as purpuric plaques and nodules that have a propensity to vesiculate and ulcerate.⁷ Histopathologically, features of leukocytoclastic vasculitis are seen, and direct immunofluorescence demonstrates perivascular granular deposits consisting predominantly of IgM and C3 in the papillary dermis.⁸

Warfarin therapy, particularly in high initial doses, can induce lesions of cutaneous necrosis, which clinically may resemble the appearance of calciphylaxis. Warfarininduced skin necrosis typically occurs 3 to 5 days after the initiation of therapy and is the result of a temporary prothrombotic state.9 The half-life of antithrombotic protein C is shorter than vitamin K–dependent prothrombotic factors II, X, and IX. Early in warfarin treatment, an acquired state of reduced protein C level exists, which can lead to vessel thrombosis and subsequent cutaneous necrosis. Treatment of warfarin-induced skin necrosis involves cessation of warfarin, supplementation with vitamin K to reverse the effects of warfarin, and the initiation of heparin or low-molecular-weight heparin.⁹

There has been increasing awareness of field cancerization in dermatology and how it relates to actinic damage, actinic keratoses (AKs), and the development of cutaneous squamous cell carcinomas (SCCs). The concept of field cancerization, which was first described in the context of oropharyngeal SCCs, attempted to explain the repeated observation of local recurrences that were instead multiple primary oropharyngeal SCCs occurring within a specific region of tissue. It was hypothesized that the tissue surrounding a malignancy also harbors irreversible oncogenic damage and therefore predisposes the surrounding tissue to developing further malignancy.¹ The development of additional malignant lesions would be considered distinct from a true recurrence of the original malignancy.

Field cancerization may be partially explained by a genetic basis, as mutations in the tumor suppressor gene, TP53—the most frequently observed mutation in cutaneous SCCs—also is found in sun-exposed but clinically normal skin.^2,3 The finding of oncogenic mutations in nonlesional skin supports the theory of field cancerization, in which a region contains multiple genetically altered populations, some of which may progress to cancer. Because there currently is no widely accepted clinical definition or validated clinical measurement of field cancerization in dermatology, it may be difficult for dermatologists to recognize which patients may be at risk for developing further malignancy in a potential area of field cancerization. Willenbrink et al⁴ updated the definition of field cancerization in dermatology as “multifocal clinical atypia characterized by AKs or SCCs in situ with or without invasive disease occurring in a field exposed to chronic UV radiation.” Managing patients with field cancerization can be challenging. Herein, we discuss updates to nonsurgical field-directed and lesion-directed therapies as well as other emerging therapies.

Field-Directed Therapies

Topical 5-fluorouracil (5-FU) and imiquimod cream 5% used as field-directed therapies help reduce the extent of AKs and actinic damage in areas of possible field cancerization.⁵ The addition of calcipotriol to topical 5-FU, which theoretically augments the skin’s T-cell antitumor response via the cytokine thymic stromal lymphopoietin, recently has been studied using short treatment courses resulting in an 87.8% reduction in AKs compared to a 26.3% reduction with topical 5-FU alone (when used twice daily for 4 days) and conferred a reduced risk of cutaneous SCCs 3 years after treatment (hazard ratio, 0.215 [95% CI, 0.048-0.972]; P=.032).^6,7 Chemowraps using topical 5-FU may be considered in more difficult-to-treat areas of field cancerization with multiple AKs or keratinocyte carcinomas of the lower extremities.⁸ The routine use of chemowraps—weekly application of 5-FU covered with an occlusive dressing—may be limited by the inability to control the extent of epidermal damage and subsequent systemic absorption. Ingenol mebutate, which was approved for treatment of AKs in 2012, was removed from both the European and US markets in 2020 because the medication may paradoxically increase the long-term incidence of skin cancer.⁹

Meta-analysis has shown that photodynamic therapy (PDT) with aminolevulinic acid demonstrated complete AK clearance in 75.8% of patients (N=156)(95% CI, 55.4%-96.2%).¹⁰ A more recent method of PDT using natural sunlight as the activation source demonstrated AK clearance of 95.5%, and it appeared to be a less painful alternative to traditional PDT.¹¹ Tacalcitol, another form of vitamin D, also has been shown to enhance the efficacy of PDT for AKs.¹²

Field-directed treatment with erbium:YAG and CO₂ lasers, which physically remove the actinically damaged epidermis, have been shown to possibly be as efficacious as topical 5-FU and 30% trichloroacetic acid (TCA) but possibly inferior to PDT.¹³ There has been growing interest in laser-assisted therapy, in which an ablative fractional laser is used to generate microscopic channels to theoretically enhance the absorption of a topical medication. A meta-analysis of the use of laser-assisted therapy for photosensitizing agents in PDT demonstrated a 33% increased chance of AK clearance compared to PDT alone (P<.01).¹⁴

Lesion-Directed Therapies

Multiple KAs or cutaneous SCCs may develop in an area of field cancerization, and surgically treating these multiple lesions in a concentrated area may be challenging. Intralesional agents, including methotrexate, 5-FU, bleomycin, and interferon, are known treatments for KAs.¹⁵ Intralesional 5-FU (25 mg once weekly for 3–4 weeks) in particular produced complete resolution in 92% of cutaneous SCCs and may be optimal for multiple or rapidly growing lesions, especially on the extremities.¹⁶

Oral Therapies

Oral therapies are considered in high-risk patients with multiple or recurrent cutaneous SCCs or in those who are immunosuppressed. Two trials demonstrated that nicotinamide 500 mg twice daily for 4 and 12 months decreased AKs by 29% to 35% and 13% (average of 3–5 fewer AKs as compared to baseline), respectively.^17,18 A meta-analysis found a reduction of cutaneous SCCs (rate ratio, 0.48 [95% CI, 0.26-0.88]; I²=67%; 552 patients, 5 trials), and given the favorable safety profile, nicotinamide can be considered for chemoprevention.¹⁹

Acitretin, shown to reduce AKs by 13.4% to 50%, is the primary oral chemoprevention recommended in transplant recipients.²⁰ Interestingly, a recent meta-analysis failed to find significant differences between the efficacy of acitretin and nicotinamide.²¹ The tolerability of acitretin requires serious consideration, as 52.2% of patients withdrew due to adverse effects in one trial.²²

Capecitabine (250–1150 mg twice daily), the oral form of 5-FU, decreased the incidence of AKs and cutaneous SCCs in 53% and 72% of transplant recipients, respectively.²³ Although several reports observed paradoxical eruptions of AKs following capecitabine for other malignancies, this actually underscores the efficacy of capecitabine, as the newly emerged AKs resolved thereafter.²⁴ Still, the evidence supporting capecitabine does not include any controlled studies.

Novel Therapies

In 2021, tirbanibulin ointment 1%, a Src tyrosine kinase inhibitor of tubulin polymerization that induces p53 expression and subsequent cell death, was approved by the US Food and Drug Administration for the treatment of AKs.²⁵ Two trials reported AK clearance rates of 44% and 54% with application of tirbanibulin once daily for 5 days (vs 5% and 13%, respectively, with placebo, each with P<.001) at 2 months and a sustained clearance rate of 27% at 1 year. The predominant adverse effects were local skin reactions, including application-site pain, pruritus, mild erythema, or scaling. Unlike in other treatments such as 5-FU or cryotherapy, erosions, dyspigmentation, or scarring were not notably observed.

Intralesional talimogene laherparepvec (T-VEC), an oncolytic, genetically modified herpes simplex virus type 1 that incites antitumor immune responses, received US Food and Drug Administration approval in 2015 for the treatment of cutaneous and lymph node metastases of melanoma that are unable to be surgically resected. More recently, T-VEC has been investigated for oropharyngeal SCC. A phase 1 and phase 2 trial of 17 stage III/IV SCC patients receiving T-VEC and cisplatin demonstrated pathologic remission in 14 of 15 (93%) patients, with 82.4% survival at 29 months.²⁶ A multicenter phase 1b trial of 36 patients with recurrent or metastatic head and neck SCCs treated with T-VEC and pembrolizumab exhibited a tolerable safety profile, and 5 cases had a partial response.²⁷ However, phase 3 trials of T-VEC have yet to be pursued. Regarding its potential use for cutaneous SCCs, it has been reportedly used in a liver transplant recipient with metastatic cutaneous SCCs who received 2 doses of T-VEC (1 month apart) and attained remission of disease.²⁸ There currently is a phase 2 trial examining the effectiveness of T-VEC in patients with cutaneous SCCs (ClinicalTrials.gov identifier NCT03714828).

Final Thoughts

It is important for dermatologists to bear in mind the possible role of field cancerization in their comprehensive care of patients at risk for multiple skin cancers. Management of areas of field cancerization can be challenging, particularly in patients who develop multiple KAs or cutaneous SCCs in a concentrated area and may need to involve different levels of treatment options, including field-directed therapies and lesion-directed therapies, as well as systemic chemoprevention.

There has been increasing awareness of field cancerization in dermatology and how it relates to actinic damage, actinic keratoses (AKs), and the development of cutaneous squamous cell carcinomas (SCCs). The concept of field cancerization, which was first described in the context of oropharyngeal SCCs, attempted to explain the repeated observation of local recurrences that were instead multiple primary oropharyngeal SCCs occurring within a specific region of tissue. It was hypothesized that the tissue surrounding a malignancy also harbors irreversible oncogenic damage and therefore predisposes the surrounding tissue to developing further malignancy.¹ The development of additional malignant lesions would be considered distinct from a true recurrence of the original malignancy.

Field cancerization may be partially explained by a genetic basis, as mutations in the tumor suppressor gene, TP53—the most frequently observed mutation in cutaneous SCCs—also is found in sun-exposed but clinically normal skin.^2,3 The finding of oncogenic mutations in nonlesional skin supports the theory of field cancerization, in which a region contains multiple genetically altered populations, some of which may progress to cancer. Because there currently is no widely accepted clinical definition or validated clinical measurement of field cancerization in dermatology, it may be difficult for dermatologists to recognize which patients may be at risk for developing further malignancy in a potential area of field cancerization. Willenbrink et al⁴ updated the definition of field cancerization in dermatology as “multifocal clinical atypia characterized by AKs or SCCs in situ with or without invasive disease occurring in a field exposed to chronic UV radiation.” Managing patients with field cancerization can be challenging. Herein, we discuss updates to nonsurgical field-directed and lesion-directed therapies as well as other emerging therapies.

Field-Directed Therapies

Topical 5-fluorouracil (5-FU) and imiquimod cream 5% used as field-directed therapies help reduce the extent of AKs and actinic damage in areas of possible field cancerization.⁵ The addition of calcipotriol to topical 5-FU, which theoretically augments the skin’s T-cell antitumor response via the cytokine thymic stromal lymphopoietin, recently has been studied using short treatment courses resulting in an 87.8% reduction in AKs compared to a 26.3% reduction with topical 5-FU alone (when used twice daily for 4 days) and conferred a reduced risk of cutaneous SCCs 3 years after treatment (hazard ratio, 0.215 [95% CI, 0.048-0.972]; P=.032).^6,7 Chemowraps using topical 5-FU may be considered in more difficult-to-treat areas of field cancerization with multiple AKs or keratinocyte carcinomas of the lower extremities.⁸ The routine use of chemowraps—weekly application of 5-FU covered with an occlusive dressing—may be limited by the inability to control the extent of epidermal damage and subsequent systemic absorption. Ingenol mebutate, which was approved for treatment of AKs in 2012, was removed from both the European and US markets in 2020 because the medication may paradoxically increase the long-term incidence of skin cancer.⁹

Meta-analysis has shown that photodynamic therapy (PDT) with aminolevulinic acid demonstrated complete AK clearance in 75.8% of patients (N=156)(95% CI, 55.4%-96.2%).¹⁰ A more recent method of PDT using natural sunlight as the activation source demonstrated AK clearance of 95.5%, and it appeared to be a less painful alternative to traditional PDT.¹¹ Tacalcitol, another form of vitamin D, also has been shown to enhance the efficacy of PDT for AKs.¹²

Field-directed treatment with erbium:YAG and CO₂ lasers, which physically remove the actinically damaged epidermis, have been shown to possibly be as efficacious as topical 5-FU and 30% trichloroacetic acid (TCA) but possibly inferior to PDT.¹³ There has been growing interest in laser-assisted therapy, in which an ablative fractional laser is used to generate microscopic channels to theoretically enhance the absorption of a topical medication. A meta-analysis of the use of laser-assisted therapy for photosensitizing agents in PDT demonstrated a 33% increased chance of AK clearance compared to PDT alone (P<.01).¹⁴

Lesion-Directed Therapies

Multiple KAs or cutaneous SCCs may develop in an area of field cancerization, and surgically treating these multiple lesions in a concentrated area may be challenging. Intralesional agents, including methotrexate, 5-FU, bleomycin, and interferon, are known treatments for KAs.¹⁵ Intralesional 5-FU (25 mg once weekly for 3–4 weeks) in particular produced complete resolution in 92% of cutaneous SCCs and may be optimal for multiple or rapidly growing lesions, especially on the extremities.¹⁶

Oral Therapies

Oral therapies are considered in high-risk patients with multiple or recurrent cutaneous SCCs or in those who are immunosuppressed. Two trials demonstrated that nicotinamide 500 mg twice daily for 4 and 12 months decreased AKs by 29% to 35% and 13% (average of 3–5 fewer AKs as compared to baseline), respectively.^17,18 A meta-analysis found a reduction of cutaneous SCCs (rate ratio, 0.48 [95% CI, 0.26-0.88]; I²=67%; 552 patients, 5 trials), and given the favorable safety profile, nicotinamide can be considered for chemoprevention.¹⁹

Acitretin, shown to reduce AKs by 13.4% to 50%, is the primary oral chemoprevention recommended in transplant recipients.²⁰ Interestingly, a recent meta-analysis failed to find significant differences between the efficacy of acitretin and nicotinamide.²¹ The tolerability of acitretin requires serious consideration, as 52.2% of patients withdrew due to adverse effects in one trial.²²

Capecitabine (250–1150 mg twice daily), the oral form of 5-FU, decreased the incidence of AKs and cutaneous SCCs in 53% and 72% of transplant recipients, respectively.²³ Although several reports observed paradoxical eruptions of AKs following capecitabine for other malignancies, this actually underscores the efficacy of capecitabine, as the newly emerged AKs resolved thereafter.²⁴ Still, the evidence supporting capecitabine does not include any controlled studies.

Novel Therapies

In 2021, tirbanibulin ointment 1%, a Src tyrosine kinase inhibitor of tubulin polymerization that induces p53 expression and subsequent cell death, was approved by the US Food and Drug Administration for the treatment of AKs.²⁵ Two trials reported AK clearance rates of 44% and 54% with application of tirbanibulin once daily for 5 days (vs 5% and 13%, respectively, with placebo, each with P<.001) at 2 months and a sustained clearance rate of 27% at 1 year. The predominant adverse effects were local skin reactions, including application-site pain, pruritus, mild erythema, or scaling. Unlike in other treatments such as 5-FU or cryotherapy, erosions, dyspigmentation, or scarring were not notably observed.

Intralesional talimogene laherparepvec (T-VEC), an oncolytic, genetically modified herpes simplex virus type 1 that incites antitumor immune responses, received US Food and Drug Administration approval in 2015 for the treatment of cutaneous and lymph node metastases of melanoma that are unable to be surgically resected. More recently, T-VEC has been investigated for oropharyngeal SCC. A phase 1 and phase 2 trial of 17 stage III/IV SCC patients receiving T-VEC and cisplatin demonstrated pathologic remission in 14 of 15 (93%) patients, with 82.4% survival at 29 months.²⁶ A multicenter phase 1b trial of 36 patients with recurrent or metastatic head and neck SCCs treated with T-VEC and pembrolizumab exhibited a tolerable safety profile, and 5 cases had a partial response.²⁷ However, phase 3 trials of T-VEC have yet to be pursued. Regarding its potential use for cutaneous SCCs, it has been reportedly used in a liver transplant recipient with metastatic cutaneous SCCs who received 2 doses of T-VEC (1 month apart) and attained remission of disease.²⁸ There currently is a phase 2 trial examining the effectiveness of T-VEC in patients with cutaneous SCCs (ClinicalTrials.gov identifier NCT03714828).

Final Thoughts

It is important for dermatologists to bear in mind the possible role of field cancerization in their comprehensive care of patients at risk for multiple skin cancers. Management of areas of field cancerization can be challenging, particularly in patients who develop multiple KAs or cutaneous SCCs in a concentrated area and may need to involve different levels of treatment options, including field-directed therapies and lesion-directed therapies, as well as systemic chemoprevention.

There has been increasing awareness of field cancerization in dermatology and how it relates to actinic damage, actinic keratoses (AKs), and the development of cutaneous squamous cell carcinomas (SCCs). The concept of field cancerization, which was first described in the context of oropharyngeal SCCs, attempted to explain the repeated observation of local recurrences that were instead multiple primary oropharyngeal SCCs occurring within a specific region of tissue. It was hypothesized that the tissue surrounding a malignancy also harbors irreversible oncogenic damage and therefore predisposes the surrounding tissue to developing further malignancy.¹ The development of additional malignant lesions would be considered distinct from a true recurrence of the original malignancy.

Field cancerization may be partially explained by a genetic basis, as mutations in the tumor suppressor gene, TP53—the most frequently observed mutation in cutaneous SCCs—also is found in sun-exposed but clinically normal skin.^2,3 The finding of oncogenic mutations in nonlesional skin supports the theory of field cancerization, in which a region contains multiple genetically altered populations, some of which may progress to cancer. Because there currently is no widely accepted clinical definition or validated clinical measurement of field cancerization in dermatology, it may be difficult for dermatologists to recognize which patients may be at risk for developing further malignancy in a potential area of field cancerization. Willenbrink et al⁴ updated the definition of field cancerization in dermatology as “multifocal clinical atypia characterized by AKs or SCCs in situ with or without invasive disease occurring in a field exposed to chronic UV radiation.” Managing patients with field cancerization can be challenging. Herein, we discuss updates to nonsurgical field-directed and lesion-directed therapies as well as other emerging therapies.

Field-Directed Therapies

Topical 5-fluorouracil (5-FU) and imiquimod cream 5% used as field-directed therapies help reduce the extent of AKs and actinic damage in areas of possible field cancerization.⁵ The addition of calcipotriol to topical 5-FU, which theoretically augments the skin’s T-cell antitumor response via the cytokine thymic stromal lymphopoietin, recently has been studied using short treatment courses resulting in an 87.8% reduction in AKs compared to a 26.3% reduction with topical 5-FU alone (when used twice daily for 4 days) and conferred a reduced risk of cutaneous SCCs 3 years after treatment (hazard ratio, 0.215 [95% CI, 0.048-0.972]; P=.032).^6,7 Chemowraps using topical 5-FU may be considered in more difficult-to-treat areas of field cancerization with multiple AKs or keratinocyte carcinomas of the lower extremities.⁸ The routine use of chemowraps—weekly application of 5-FU covered with an occlusive dressing—may be limited by the inability to control the extent of epidermal damage and subsequent systemic absorption. Ingenol mebutate, which was approved for treatment of AKs in 2012, was removed from both the European and US markets in 2020 because the medication may paradoxically increase the long-term incidence of skin cancer.⁹

Meta-analysis has shown that photodynamic therapy (PDT) with aminolevulinic acid demonstrated complete AK clearance in 75.8% of patients (N=156)(95% CI, 55.4%-96.2%).¹⁰ A more recent method of PDT using natural sunlight as the activation source demonstrated AK clearance of 95.5%, and it appeared to be a less painful alternative to traditional PDT.¹¹ Tacalcitol, another form of vitamin D, also has been shown to enhance the efficacy of PDT for AKs.¹²

Field-directed treatment with erbium:YAG and CO₂ lasers, which physically remove the actinically damaged epidermis, have been shown to possibly be as efficacious as topical 5-FU and 30% trichloroacetic acid (TCA) but possibly inferior to PDT.¹³ There has been growing interest in laser-assisted therapy, in which an ablative fractional laser is used to generate microscopic channels to theoretically enhance the absorption of a topical medication. A meta-analysis of the use of laser-assisted therapy for photosensitizing agents in PDT demonstrated a 33% increased chance of AK clearance compared to PDT alone (P<.01).¹⁴

Lesion-Directed Therapies

Multiple KAs or cutaneous SCCs may develop in an area of field cancerization, and surgically treating these multiple lesions in a concentrated area may be challenging. Intralesional agents, including methotrexate, 5-FU, bleomycin, and interferon, are known treatments for KAs.¹⁵ Intralesional 5-FU (25 mg once weekly for 3–4 weeks) in particular produced complete resolution in 92% of cutaneous SCCs and may be optimal for multiple or rapidly growing lesions, especially on the extremities.¹⁶

Oral Therapies

Oral therapies are considered in high-risk patients with multiple or recurrent cutaneous SCCs or in those who are immunosuppressed. Two trials demonstrated that nicotinamide 500 mg twice daily for 4 and 12 months decreased AKs by 29% to 35% and 13% (average of 3–5 fewer AKs as compared to baseline), respectively.^17,18 A meta-analysis found a reduction of cutaneous SCCs (rate ratio, 0.48 [95% CI, 0.26-0.88]; I²=67%; 552 patients, 5 trials), and given the favorable safety profile, nicotinamide can be considered for chemoprevention.¹⁹

Acitretin, shown to reduce AKs by 13.4% to 50%, is the primary oral chemoprevention recommended in transplant recipients.²⁰ Interestingly, a recent meta-analysis failed to find significant differences between the efficacy of acitretin and nicotinamide.²¹ The tolerability of acitretin requires serious consideration, as 52.2% of patients withdrew due to adverse effects in one trial.²²

Capecitabine (250–1150 mg twice daily), the oral form of 5-FU, decreased the incidence of AKs and cutaneous SCCs in 53% and 72% of transplant recipients, respectively.²³ Although several reports observed paradoxical eruptions of AKs following capecitabine for other malignancies, this actually underscores the efficacy of capecitabine, as the newly emerged AKs resolved thereafter.²⁴ Still, the evidence supporting capecitabine does not include any controlled studies.

Novel Therapies

In 2021, tirbanibulin ointment 1%, a Src tyrosine kinase inhibitor of tubulin polymerization that induces p53 expression and subsequent cell death, was approved by the US Food and Drug Administration for the treatment of AKs.²⁵ Two trials reported AK clearance rates of 44% and 54% with application of tirbanibulin once daily for 5 days (vs 5% and 13%, respectively, with placebo, each with P<.001) at 2 months and a sustained clearance rate of 27% at 1 year. The predominant adverse effects were local skin reactions, including application-site pain, pruritus, mild erythema, or scaling. Unlike in other treatments such as 5-FU or cryotherapy, erosions, dyspigmentation, or scarring were not notably observed.

Intralesional talimogene laherparepvec (T-VEC), an oncolytic, genetically modified herpes simplex virus type 1 that incites antitumor immune responses, received US Food and Drug Administration approval in 2015 for the treatment of cutaneous and lymph node metastases of melanoma that are unable to be surgically resected. More recently, T-VEC has been investigated for oropharyngeal SCC. A phase 1 and phase 2 trial of 17 stage III/IV SCC patients receiving T-VEC and cisplatin demonstrated pathologic remission in 14 of 15 (93%) patients, with 82.4% survival at 29 months.²⁶ A multicenter phase 1b trial of 36 patients with recurrent or metastatic head and neck SCCs treated with T-VEC and pembrolizumab exhibited a tolerable safety profile, and 5 cases had a partial response.²⁷ However, phase 3 trials of T-VEC have yet to be pursued. Regarding its potential use for cutaneous SCCs, it has been reportedly used in a liver transplant recipient with metastatic cutaneous SCCs who received 2 doses of T-VEC (1 month apart) and attained remission of disease.²⁸ There currently is a phase 2 trial examining the effectiveness of T-VEC in patients with cutaneous SCCs (ClinicalTrials.gov identifier NCT03714828).

Final Thoughts

It is important for dermatologists to bear in mind the possible role of field cancerization in their comprehensive care of patients at risk for multiple skin cancers. Management of areas of field cancerization can be challenging, particularly in patients who develop multiple KAs or cutaneous SCCs in a concentrated area and may need to involve different levels of treatment options, including field-directed therapies and lesion-directed therapies, as well as systemic chemoprevention.

Approximately 50% of melanomas contain BRAF mutations, which occur in a greater proportion of melanomas found on sites of intermittent sun exposure.¹BRAF-mutated melanomas have been associated with high levels of early-life ambient UV exposure, especially between ages 0 and 20 years.² In addition, studies have shown that BRAF-mutated melanomas commonly are found on the trunk and extremities.^1-3BRAF mutations also have been associated with younger age, superficial spreading subtype and low tumor thickness, absence of dermal melanocyte mitosis, low Ki-67 score, low phospho-histone H3 score, pigmented melanoma, advanced melanoma stage, and conjunctival melanoma.^4-7BRAF mutations are found more frequently in metastatic melanoma lesions than primary melanomas, suggesting that BRAF mutations may be acquired during metastasis.⁸ Studies have shown different conclusions on the effect of BRAF mutation on melanoma-related death.^5,9,10

The aim of this study was to identify trends in BRAF V600E–mutated melanoma according to age, sex, and melanoma-specific survival among Olmsted County, Minnesota, residents with a first diagnosis of melanoma at 18 to 60 years of age.

Methods

In total, 638 patients aged 18 to 60 years who resided in Olmsted County and had a first lifetime diagnosis of cutaneous melanoma between 1970 and 2009 were retrospectively identified as a part of the Rochester Epidemiology Project (REP). The REP is a health records linkage system that encompasses almost all sources of medical care available to the local population of Olmsted County.¹¹ This study was approved by the Mayo Clinic Institutional Review Board (Rochester, Minnesota).

Of the 638 individuals identified in the REP, 536 had been seen at Mayo Clinic and thus potentially had tissue blocks available for the study of BRAF mutation expression. Of these 536 patients, 156 did not have sufficient residual tissue available. As a result, 380 (60%) of the original 638 patients had available blocks with sufficient tissue for immunohistochemical analysis of BRAF expression. Only primary cutaneous melanomas were included in the present study.

All specimens were reviewed by a board-certified dermatopathologist (J.S.L.) for appropriateness of inclusion, which involved confirmation of the diagnosis of melanoma, histologic type of melanoma, and presence of sufficient residual tissue for immunohistochemical stains.

All specimens were originally diagnosed as malignant melanoma at the time of clinical care by at least 2 board-certified dermatopathologists. For the purposes of this study, all specimens were rereviewed for diagnostic accuracy. We required that specimens exhibit severe cytologic and architectural atypia as well as other features favoring melanoma, such as consumption of rete pegs, pagetosis, confluence of junctional melanocytes, evidence of regression, lack of maturation of melanocytes with descent into the dermis, or mitotic figures among the dermal melanocyte population.

The available tissue blocks were retrieved, sectioned, confirmed as melanoma, and stained with a mouse antihuman BRAF V600E monoclonal antibody (clone VE1; Spring Bioscience) to determine the presence of a BRAF V600E mutation. BRAF staining was evaluated in conjunction with a review of the associated slides stained with hematoxylin and eosin. Cytoplasmic staining of melanocytes for BRAF was graded as negative, focal or partial positive (<50% of tumor), or diffuse positive (>50% of tumor)(Figure 1). When a melanoma arose in association with a nevus, we considered only the melanoma component for BRAF staining. We categorized the histologic type as superficial spreading, nodular, or lentigo maligna, and the location as head and neck, trunk, or extremities.

Results

Clinical and Tumor Characteristics—Of the 380 tissue specimens that underwent BRAF V600E analysis, 247 had negative staining; 106 had diffuse strong staining; and 27 had focal or partial staining. In total, 133 (35%) were positive, either partially or diffusely. The median age for patients who had negative staining was 45 years; for those with positive staining, it was 41 years (P=.07).

The patients who met inclusion criteria (n=380) were compared with those who were excluded (n=258)(eTable 1). The groups were similar on the basis of sex; age; and melanoma location, stage, and histologic subtype. However, some evidence showed that patients included in the study received the diagnosis of melanoma more recently (1970-1989, 13.2%; 1990-1999, 28.7%; 2000-2009, 58.2%) than those who were excluded (1970-1989, 24.7%; 1990-1999, 23.5%; 2000-2009, 51.8%)(P=.02).

BRAF V600E expression was more commonly found in superficial spreading (37.7%) and nodular melanomas (35.0%) than in situ melanomas (17.1%)(P=.01). Other characteristics of BRAF V600E expression are described in eTable 2. Overall, invasive and advanced melanomas were significantly more likely to harbor BRAF V600E expression than noninvasive melanomas (39.6% and 37.9%, respectively, vs 17.9%; P=.003). However, advanced melanomas more commonly expressed BRAF positivity among women, and invasive melanomas more commonly expressed BRAF positivity among men (eTable 2).

Survival—Survival analyses were limited to 297 patients with confirmed invasive or advanced disease. Of these, 180 (61%) had no BRAF V600E staining; 25 (8%) had partial staining; and 92 (31%) had diffuse positive staining. In total, 117 patients (39%) had a BRAF-mutated melanoma.

Among the patients still alive, the median (interquartile range [IQR]) duration of follow-up was 10.2 (7.0-16.8) years. Thirty-nine patients with invasive or advanced disease had died of any cause at a median (IQR) of 3.0 (1.3-10.2) years after diagnosis. In total, 26 patients died of melanoma at a median (IQR) follow-up of 2.5 (1.3-7.4) years after diagnosis. Eight women and 18 men died of malignant melanoma. Five deaths occurred because of malignant melanoma among patients aged 18 to 39 years, and 21 occurred among patients aged 40 to 60 years. In the 18- to 39-year-old group, all 5 deaths were among patients with a BRAF-positive melanoma. Estimated disease-specific survival rate (95% CI; number still at risk) at 5, 10, 15, and 20 years after diagnosis was 94% (91%-97%; 243), 91% (87%-95%; 142), 89% (85%-94%; 87), and 88% (83%-93%; 45), respectively.

Comment

We found that melanomas with BRAF mutations were more likely in advanced and invasive melanoma. The frequency of BRAF mutations among melanomas that were considered advanced was higher in women than men. Although the number of deaths was limited, women with a melanoma with BRAF expression were more likely to die of melanoma, young adults with a BRAF-mutated melanoma had an almost 10-fold increased risk of dying from any cause, and middle-aged adults showed no increased risk of death. These findings suggest that young adults who are genetically prone to a BRAF-mutated melanoma could be at a disadvantage for all-cause mortality. Although this finding was significant, the 95% CI was large, and further studies would be warranted before sound conclusions could be made.

Melanoma has been increasing in incidence across all age groups in Olmsted County over the last 4 decades.^12-14 However, our results show that the percentage of BRAF-mutated melanomas in this population has been stable over time, with no statistically significant difference by age or sex. Other confounding factors may have an influence, such as increased rates of early detection and diagnosis of melanoma in contemporary times. Our data suggest that patients included in the BRAF-mutation analysis study had received the diagnosis of melanoma more recently than those who were excluded from the study, which could be due to older melanomas being less likely to have adequate tissue specimens available for immunohistochemical staining/evaluation.

Prior research has shown that BRAF-mutated melanomas typically occur on the trunk and are more likely in individuals with more than 14 nevi on the back.² In the present cohort, BRAF-positive melanomas had a predisposition toward the trunk but also were found on the head, neck, and extremities—areas that are more likely to have long-term sun damage. One suggestion is that 2 distinct pathways for melanoma development exist: one associated with a large number of melanocytic nevi (that is more prone to genetic mutations in melanocytes) and the other associated with long-term sun exposure.^15,16 The combination of these hypotheses suggests that individuals who are prone to the development of large numbers of nevi may require sun exposure for the initial insult, but the development of melanoma may be carried out by other factors after this initial sun exposure insult, whereas individuals without large numbers of nevi who may have less genetic risk may require continued long-term sun exposure for melanoma to develop.¹⁷

Our study had limitations, including the small numbers of deaths overall and cause-specific deaths of metastatic melanoma, which limited our ability to conduct more extensive multivariable modeling. Also, the retrospective nature and time frame of looking back 4 decades did not allow us to have information sufficient to categorize some patients as having dysplastic nevus syndrome or not, which would be a potentially interesting variable to include in the analysis. Because the number of deaths in the 18- to 39-year-old cohort was only 5, further statistical comparison regarding tumor type and other variables pertaining to BRAF positivity were not possible. In addition, our data were collected from patients residing in a single geographic county (Olmsted County, Minnesota), which may limit generalizability. Lastly, BRAF V600E mutations were identified through immunostaining only, not molecular data, so it is possible some patients had false-negative immunohistochemistry findings and thus were not identified.

Conclusion

BRAF-mutated melanomas were found in 35% of our cohort, with no significant change in the percentage of melanomas with BRAF V600E mutations over the last 4 decades in this population. In addition, no differences or significant trends existed according to sex and BRAF-mutated melanoma development. Women with BRAF-mutated melanomas were more likely to die of metastatic melanoma than men, and young adults with BRAF-mutated melanomas had a higher all-cause mortality risk. Further research is needed to decipher what effect BRAF-mutated melanomas have on metastasis and cause-specific death in women as well as all-cause mortality in young adults.

Acknowledgment—The authors are indebted to Scientific Publications, Mayo Clinic (Rochester, Minnesota).

Approximately 50% of melanomas contain BRAF mutations, which occur in a greater proportion of melanomas found on sites of intermittent sun exposure.¹BRAF-mutated melanomas have been associated with high levels of early-life ambient UV exposure, especially between ages 0 and 20 years.² In addition, studies have shown that BRAF-mutated melanomas commonly are found on the trunk and extremities.^1-3BRAF mutations also have been associated with younger age, superficial spreading subtype and low tumor thickness, absence of dermal melanocyte mitosis, low Ki-67 score, low phospho-histone H3 score, pigmented melanoma, advanced melanoma stage, and conjunctival melanoma.^4-7BRAF mutations are found more frequently in metastatic melanoma lesions than primary melanomas, suggesting that BRAF mutations may be acquired during metastasis.⁸ Studies have shown different conclusions on the effect of BRAF mutation on melanoma-related death.^5,9,10

The aim of this study was to identify trends in BRAF V600E–mutated melanoma according to age, sex, and melanoma-specific survival among Olmsted County, Minnesota, residents with a first diagnosis of melanoma at 18 to 60 years of age.

Methods

In total, 638 patients aged 18 to 60 years who resided in Olmsted County and had a first lifetime diagnosis of cutaneous melanoma between 1970 and 2009 were retrospectively identified as a part of the Rochester Epidemiology Project (REP). The REP is a health records linkage system that encompasses almost all sources of medical care available to the local population of Olmsted County.¹¹ This study was approved by the Mayo Clinic Institutional Review Board (Rochester, Minnesota).

Of the 638 individuals identified in the REP, 536 had been seen at Mayo Clinic and thus potentially had tissue blocks available for the study of BRAF mutation expression. Of these 536 patients, 156 did not have sufficient residual tissue available. As a result, 380 (60%) of the original 638 patients had available blocks with sufficient tissue for immunohistochemical analysis of BRAF expression. Only primary cutaneous melanomas were included in the present study.

All specimens were reviewed by a board-certified dermatopathologist (J.S.L.) for appropriateness of inclusion, which involved confirmation of the diagnosis of melanoma, histologic type of melanoma, and presence of sufficient residual tissue for immunohistochemical stains.

All specimens were originally diagnosed as malignant melanoma at the time of clinical care by at least 2 board-certified dermatopathologists. For the purposes of this study, all specimens were rereviewed for diagnostic accuracy. We required that specimens exhibit severe cytologic and architectural atypia as well as other features favoring melanoma, such as consumption of rete pegs, pagetosis, confluence of junctional melanocytes, evidence of regression, lack of maturation of melanocytes with descent into the dermis, or mitotic figures among the dermal melanocyte population.

The available tissue blocks were retrieved, sectioned, confirmed as melanoma, and stained with a mouse antihuman BRAF V600E monoclonal antibody (clone VE1; Spring Bioscience) to determine the presence of a BRAF V600E mutation. BRAF staining was evaluated in conjunction with a review of the associated slides stained with hematoxylin and eosin. Cytoplasmic staining of melanocytes for BRAF was graded as negative, focal or partial positive (<50% of tumor), or diffuse positive (>50% of tumor)(Figure 1). When a melanoma arose in association with a nevus, we considered only the melanoma component for BRAF staining. We categorized the histologic type as superficial spreading, nodular, or lentigo maligna, and the location as head and neck, trunk, or extremities.

Results

Clinical and Tumor Characteristics—Of the 380 tissue specimens that underwent BRAF V600E analysis, 247 had negative staining; 106 had diffuse strong staining; and 27 had focal or partial staining. In total, 133 (35%) were positive, either partially or diffusely. The median age for patients who had negative staining was 45 years; for those with positive staining, it was 41 years (P=.07).

The patients who met inclusion criteria (n=380) were compared with those who were excluded (n=258)(eTable 1). The groups were similar on the basis of sex; age; and melanoma location, stage, and histologic subtype. However, some evidence showed that patients included in the study received the diagnosis of melanoma more recently (1970-1989, 13.2%; 1990-1999, 28.7%; 2000-2009, 58.2%) than those who were excluded (1970-1989, 24.7%; 1990-1999, 23.5%; 2000-2009, 51.8%)(P=.02).

BRAF V600E expression was more commonly found in superficial spreading (37.7%) and nodular melanomas (35.0%) than in situ melanomas (17.1%)(P=.01). Other characteristics of BRAF V600E expression are described in eTable 2. Overall, invasive and advanced melanomas were significantly more likely to harbor BRAF V600E expression than noninvasive melanomas (39.6% and 37.9%, respectively, vs 17.9%; P=.003). However, advanced melanomas more commonly expressed BRAF positivity among women, and invasive melanomas more commonly expressed BRAF positivity among men (eTable 2).

Survival—Survival analyses were limited to 297 patients with confirmed invasive or advanced disease. Of these, 180 (61%) had no BRAF V600E staining; 25 (8%) had partial staining; and 92 (31%) had diffuse positive staining. In total, 117 patients (39%) had a BRAF-mutated melanoma.

Among the patients still alive, the median (interquartile range [IQR]) duration of follow-up was 10.2 (7.0-16.8) years. Thirty-nine patients with invasive or advanced disease had died of any cause at a median (IQR) of 3.0 (1.3-10.2) years after diagnosis. In total, 26 patients died of melanoma at a median (IQR) follow-up of 2.5 (1.3-7.4) years after diagnosis. Eight women and 18 men died of malignant melanoma. Five deaths occurred because of malignant melanoma among patients aged 18 to 39 years, and 21 occurred among patients aged 40 to 60 years. In the 18- to 39-year-old group, all 5 deaths were among patients with a BRAF-positive melanoma. Estimated disease-specific survival rate (95% CI; number still at risk) at 5, 10, 15, and 20 years after diagnosis was 94% (91%-97%; 243), 91% (87%-95%; 142), 89% (85%-94%; 87), and 88% (83%-93%; 45), respectively.

Comment

We found that melanomas with BRAF mutations were more likely in advanced and invasive melanoma. The frequency of BRAF mutations among melanomas that were considered advanced was higher in women than men. Although the number of deaths was limited, women with a melanoma with BRAF expression were more likely to die of melanoma, young adults with a BRAF-mutated melanoma had an almost 10-fold increased risk of dying from any cause, and middle-aged adults showed no increased risk of death. These findings suggest that young adults who are genetically prone to a BRAF-mutated melanoma could be at a disadvantage for all-cause mortality. Although this finding was significant, the 95% CI was large, and further studies would be warranted before sound conclusions could be made.

Melanoma has been increasing in incidence across all age groups in Olmsted County over the last 4 decades.^12-14 However, our results show that the percentage of BRAF-mutated melanomas in this population has been stable over time, with no statistically significant difference by age or sex. Other confounding factors may have an influence, such as increased rates of early detection and diagnosis of melanoma in contemporary times. Our data suggest that patients included in the BRAF-mutation analysis study had received the diagnosis of melanoma more recently than those who were excluded from the study, which could be due to older melanomas being less likely to have adequate tissue specimens available for immunohistochemical staining/evaluation.

Prior research has shown that BRAF-mutated melanomas typically occur on the trunk and are more likely in individuals with more than 14 nevi on the back.² In the present cohort, BRAF-positive melanomas had a predisposition toward the trunk but also were found on the head, neck, and extremities—areas that are more likely to have long-term sun damage. One suggestion is that 2 distinct pathways for melanoma development exist: one associated with a large number of melanocytic nevi (that is more prone to genetic mutations in melanocytes) and the other associated with long-term sun exposure.^15,16 The combination of these hypotheses suggests that individuals who are prone to the development of large numbers of nevi may require sun exposure for the initial insult, but the development of melanoma may be carried out by other factors after this initial sun exposure insult, whereas individuals without large numbers of nevi who may have less genetic risk may require continued long-term sun exposure for melanoma to develop.¹⁷

Our study had limitations, including the small numbers of deaths overall and cause-specific deaths of metastatic melanoma, which limited our ability to conduct more extensive multivariable modeling. Also, the retrospective nature and time frame of looking back 4 decades did not allow us to have information sufficient to categorize some patients as having dysplastic nevus syndrome or not, which would be a potentially interesting variable to include in the analysis. Because the number of deaths in the 18- to 39-year-old cohort was only 5, further statistical comparison regarding tumor type and other variables pertaining to BRAF positivity were not possible. In addition, our data were collected from patients residing in a single geographic county (Olmsted County, Minnesota), which may limit generalizability. Lastly, BRAF V600E mutations were identified through immunostaining only, not molecular data, so it is possible some patients had false-negative immunohistochemistry findings and thus were not identified.

Conclusion

BRAF-mutated melanomas were found in 35% of our cohort, with no significant change in the percentage of melanomas with BRAF V600E mutations over the last 4 decades in this population. In addition, no differences or significant trends existed according to sex and BRAF-mutated melanoma development. Women with BRAF-mutated melanomas were more likely to die of metastatic melanoma than men, and young adults with BRAF-mutated melanomas had a higher all-cause mortality risk. Further research is needed to decipher what effect BRAF-mutated melanomas have on metastasis and cause-specific death in women as well as all-cause mortality in young adults.

Acknowledgment—The authors are indebted to Scientific Publications, Mayo Clinic (Rochester, Minnesota).

Approximately 50% of melanomas contain BRAF mutations, which occur in a greater proportion of melanomas found on sites of intermittent sun exposure.¹BRAF-mutated melanomas have been associated with high levels of early-life ambient UV exposure, especially between ages 0 and 20 years.² In addition, studies have shown that BRAF-mutated melanomas commonly are found on the trunk and extremities.^1-3BRAF mutations also have been associated with younger age, superficial spreading subtype and low tumor thickness, absence of dermal melanocyte mitosis, low Ki-67 score, low phospho-histone H3 score, pigmented melanoma, advanced melanoma stage, and conjunctival melanoma.^4-7BRAF mutations are found more frequently in metastatic melanoma lesions than primary melanomas, suggesting that BRAF mutations may be acquired during metastasis.⁸ Studies have shown different conclusions on the effect of BRAF mutation on melanoma-related death.^5,9,10

The aim of this study was to identify trends in BRAF V600E–mutated melanoma according to age, sex, and melanoma-specific survival among Olmsted County, Minnesota, residents with a first diagnosis of melanoma at 18 to 60 years of age.

Methods

In total, 638 patients aged 18 to 60 years who resided in Olmsted County and had a first lifetime diagnosis of cutaneous melanoma between 1970 and 2009 were retrospectively identified as a part of the Rochester Epidemiology Project (REP). The REP is a health records linkage system that encompasses almost all sources of medical care available to the local population of Olmsted County.¹¹ This study was approved by the Mayo Clinic Institutional Review Board (Rochester, Minnesota).

Of the 638 individuals identified in the REP, 536 had been seen at Mayo Clinic and thus potentially had tissue blocks available for the study of BRAF mutation expression. Of these 536 patients, 156 did not have sufficient residual tissue available. As a result, 380 (60%) of the original 638 patients had available blocks with sufficient tissue for immunohistochemical analysis of BRAF expression. Only primary cutaneous melanomas were included in the present study.

All specimens were reviewed by a board-certified dermatopathologist (J.S.L.) for appropriateness of inclusion, which involved confirmation of the diagnosis of melanoma, histologic type of melanoma, and presence of sufficient residual tissue for immunohistochemical stains.

All specimens were originally diagnosed as malignant melanoma at the time of clinical care by at least 2 board-certified dermatopathologists. For the purposes of this study, all specimens were rereviewed for diagnostic accuracy. We required that specimens exhibit severe cytologic and architectural atypia as well as other features favoring melanoma, such as consumption of rete pegs, pagetosis, confluence of junctional melanocytes, evidence of regression, lack of maturation of melanocytes with descent into the dermis, or mitotic figures among the dermal melanocyte population.

The available tissue blocks were retrieved, sectioned, confirmed as melanoma, and stained with a mouse antihuman BRAF V600E monoclonal antibody (clone VE1; Spring Bioscience) to determine the presence of a BRAF V600E mutation. BRAF staining was evaluated in conjunction with a review of the associated slides stained with hematoxylin and eosin. Cytoplasmic staining of melanocytes for BRAF was graded as negative, focal or partial positive (<50% of tumor), or diffuse positive (>50% of tumor)(Figure 1). When a melanoma arose in association with a nevus, we considered only the melanoma component for BRAF staining. We categorized the histologic type as superficial spreading, nodular, or lentigo maligna, and the location as head and neck, trunk, or extremities.

Results

Clinical and Tumor Characteristics—Of the 380 tissue specimens that underwent BRAF V600E analysis, 247 had negative staining; 106 had diffuse strong staining; and 27 had focal or partial staining. In total, 133 (35%) were positive, either partially or diffusely. The median age for patients who had negative staining was 45 years; for those with positive staining, it was 41 years (P=.07).

The patients who met inclusion criteria (n=380) were compared with those who were excluded (n=258)(eTable 1). The groups were similar on the basis of sex; age; and melanoma location, stage, and histologic subtype. However, some evidence showed that patients included in the study received the diagnosis of melanoma more recently (1970-1989, 13.2%; 1990-1999, 28.7%; 2000-2009, 58.2%) than those who were excluded (1970-1989, 24.7%; 1990-1999, 23.5%; 2000-2009, 51.8%)(P=.02).

BRAF V600E expression was more commonly found in superficial spreading (37.7%) and nodular melanomas (35.0%) than in situ melanomas (17.1%)(P=.01). Other characteristics of BRAF V600E expression are described in eTable 2. Overall, invasive and advanced melanomas were significantly more likely to harbor BRAF V600E expression than noninvasive melanomas (39.6% and 37.9%, respectively, vs 17.9%; P=.003). However, advanced melanomas more commonly expressed BRAF positivity among women, and invasive melanomas more commonly expressed BRAF positivity among men (eTable 2).

Survival—Survival analyses were limited to 297 patients with confirmed invasive or advanced disease. Of these, 180 (61%) had no BRAF V600E staining; 25 (8%) had partial staining; and 92 (31%) had diffuse positive staining. In total, 117 patients (39%) had a BRAF-mutated melanoma.

Among the patients still alive, the median (interquartile range [IQR]) duration of follow-up was 10.2 (7.0-16.8) years. Thirty-nine patients with invasive or advanced disease had died of any cause at a median (IQR) of 3.0 (1.3-10.2) years after diagnosis. In total, 26 patients died of melanoma at a median (IQR) follow-up of 2.5 (1.3-7.4) years after diagnosis. Eight women and 18 men died of malignant melanoma. Five deaths occurred because of malignant melanoma among patients aged 18 to 39 years, and 21 occurred among patients aged 40 to 60 years. In the 18- to 39-year-old group, all 5 deaths were among patients with a BRAF-positive melanoma. Estimated disease-specific survival rate (95% CI; number still at risk) at 5, 10, 15, and 20 years after diagnosis was 94% (91%-97%; 243), 91% (87%-95%; 142), 89% (85%-94%; 87), and 88% (83%-93%; 45), respectively.

Comment

We found that melanomas with BRAF mutations were more likely in advanced and invasive melanoma. The frequency of BRAF mutations among melanomas that were considered advanced was higher in women than men. Although the number of deaths was limited, women with a melanoma with BRAF expression were more likely to die of melanoma, young adults with a BRAF-mutated melanoma had an almost 10-fold increased risk of dying from any cause, and middle-aged adults showed no increased risk of death. These findings suggest that young adults who are genetically prone to a BRAF-mutated melanoma could be at a disadvantage for all-cause mortality. Although this finding was significant, the 95% CI was large, and further studies would be warranted before sound conclusions could be made.

Melanoma has been increasing in incidence across all age groups in Olmsted County over the last 4 decades.^12-14 However, our results show that the percentage of BRAF-mutated melanomas in this population has been stable over time, with no statistically significant difference by age or sex. Other confounding factors may have an influence, such as increased rates of early detection and diagnosis of melanoma in contemporary times. Our data suggest that patients included in the BRAF-mutation analysis study had received the diagnosis of melanoma more recently than those who were excluded from the study, which could be due to older melanomas being less likely to have adequate tissue specimens available for immunohistochemical staining/evaluation.

Prior research has shown that BRAF-mutated melanomas typically occur on the trunk and are more likely in individuals with more than 14 nevi on the back.² In the present cohort, BRAF-positive melanomas had a predisposition toward the trunk but also were found on the head, neck, and extremities—areas that are more likely to have long-term sun damage. One suggestion is that 2 distinct pathways for melanoma development exist: one associated with a large number of melanocytic nevi (that is more prone to genetic mutations in melanocytes) and the other associated with long-term sun exposure.^15,16 The combination of these hypotheses suggests that individuals who are prone to the development of large numbers of nevi may require sun exposure for the initial insult, but the development of melanoma may be carried out by other factors after this initial sun exposure insult, whereas individuals without large numbers of nevi who may have less genetic risk may require continued long-term sun exposure for melanoma to develop.¹⁷

Our study had limitations, including the small numbers of deaths overall and cause-specific deaths of metastatic melanoma, which limited our ability to conduct more extensive multivariable modeling. Also, the retrospective nature and time frame of looking back 4 decades did not allow us to have information sufficient to categorize some patients as having dysplastic nevus syndrome or not, which would be a potentially interesting variable to include in the analysis. Because the number of deaths in the 18- to 39-year-old cohort was only 5, further statistical comparison regarding tumor type and other variables pertaining to BRAF positivity were not possible. In addition, our data were collected from patients residing in a single geographic county (Olmsted County, Minnesota), which may limit generalizability. Lastly, BRAF V600E mutations were identified through immunostaining only, not molecular data, so it is possible some patients had false-negative immunohistochemistry findings and thus were not identified.

Conclusion

BRAF-mutated melanomas were found in 35% of our cohort, with no significant change in the percentage of melanomas with BRAF V600E mutations over the last 4 decades in this population. In addition, no differences or significant trends existed according to sex and BRAF-mutated melanoma development. Women with BRAF-mutated melanomas were more likely to die of metastatic melanoma than men, and young adults with BRAF-mutated melanomas had a higher all-cause mortality risk. Further research is needed to decipher what effect BRAF-mutated melanomas have on metastasis and cause-specific death in women as well as all-cause mortality in young adults.

Acknowledgment—The authors are indebted to Scientific Publications, Mayo Clinic (Rochester, Minnesota).

The COVID-19 pandemic has brought about unprecedented changes and challenges to medical practice, including new public health measure legislation, local and national medical authority recommendations, nursing home and other ancillary health center protocols, and novel clinical decision-making considerations.^1-3 In July 2020, the American Academy of Dermatology (AAD) addressed the changing landscape in dermatologic surgery, in part, by publishing recommendations on practice protocols during the COVID-19 pandemic.⁴ The guidelines recommended deferred treatment of superficial basal cell carcinomas (BCCs) for 6 months and all other BCC subtypes for 3 to 6 months. Furthermore, the guidelines recommended deferring treatment of all actinic keratoses and squamous cell carcinomas (SCCs) in situ “for now.” Squamous cell carcinoma treatment was to be guided by prognostic variables, such as location, size, depth, differentiation, perineural or lymphovascular invasion, recurrence, and immunosuppression. The guidelines recommended melanoma in situ (MIS) treatment be deferred for 3 months and invasive melanoma with histologic clearance obtained on excisional biopsy for 3 months. Other general recommendations included triaging clinics, rebooking according to clinical priority, using telehealth where possible, screening patients for COVID-19 signs and symptoms, staggering appointment times, spacing patient chairs, limiting support persons to 1, removing possible sources of infection in the waiting room, ensuring all patients sanitized their hands on arrival, rationing personal protective equipment, considering N95 masks for periorificial surgery, and using dissolving sutures to minimize multiple presentations.⁴

The American College of Mohs Surgery (ACMS), with guidance from its sister societies and the National Comprehensive Cancer Network, also communicated COVID-19–related recommendations to its members via intermittent newsletters during the initial peak of the pandemic in March and June 2020.⁵ General social distancing and office recommendations were similar to those released by the AAD. Recommendations for skin cancer treatment included deferring all BCCs for up to 3 months, with exceptions for highly symptomatic cancers and those with potential for substantial rapid growth. Squamous cell carcinoma in situ and small, well-differentiated SCCs were deferred, with priority placed on SCCs that were rapidly enlarging, poorly differentiated, demonstrated perineural invasion, were ulcerated, or were symptomatic. Patients with major risk factors were prioritized for treatment. Melanoma in situ was deferred for 2 to 3 months.⁵

State-level guidance from the Texas Dermatological Society (TDS) communicated in April 2020 stated that skin cancers with a potential for rapid progression and metastasis, such as melanoma and SCC, may require treatment as determined by the physician.⁶ The potential risk of serious adverse medical outcomes from not treating these cancers should be carefully documented. General practice measures for preventing the spread of COVID-19 were also recommended.⁶

In the setting of emerging novel recommendations, the practice of Mohs micrographic surgery (MMS) was notably impacted by the COVID-19 pandemic. According to one survey study from the United Kingdom conducted in April and May 2020, 49% of MMS services ceased and 36% were reduced during the infancy of the COVID-19 pandemic.⁷ Mohs micrographic surgery was largely suspended because of a lack of personal protective equipment and safety concerns, according to respondents. Additionally, respondents reported 77% of departments experienced redeployment of physicians and nurses to intensive care and medical wards. Thirty-five percent reported a reduction in the proportion of flaps/grafts to primary closures performed, 74% reported a decrease in outside referrals for repair by other specialties, 81% reported increased usage of dissolvable sutures, and 29% reported an increase in prophylactic antibiotic prescriptions.⁷ Another study from Italy reported a 46.5% reduction in dermatologic surgeries performed during the initial lockdown of the COVID-19 pandemic. Patients canceled 52.9% of procedures, and 12.5% were cancelled because of confirmed or suspected COVID-19 infection.⁸ Patient perceptions of MMS have also been impacted by the COVID-19 pandemic. According to a survey study of patients in the United Kingdom undergoing MMS during the pandemic, 47% were worried the hospital would cancel their surgery, 54% were anxious about using public transportation to attend their appointment, 30% were concerned about transmitting COVID-19 to household or family members, and 19% were worried about their ability to socially distance in the hospital.⁹

Evidence is also emerging that suggests the potential negative impact of the COVID-19 pandemic on morbidity and mortality outcomes in patients with skin cancer. One European study found an increase in Breslow thickness in primary melanomas diagnosed following the initial COVID-19 lockdown (0.88-mm average thickness prelockdown vs 1.96-mm average thickness postlockdown).¹⁰ An Italian study observed similar results—an increase in median Breslow thickness during the initial COVID-19 lockdown period of 0.5 mm from 0.4 mm during the prelockdown time period.¹¹ Also providing evidence for potentially poor patient outcomes, one study modeled the impact of backlog in cutaneous melanoma referrals in the United Kingdom on patient survival and predicted 138 attributable lives lost for a 1-month delay and 1171 lives lost for a 6-month delay. The model further predicted a 3.1% to 12.5% reduction in 10-year net survival incurred from a 3-month delay in melanoma treatment, with the largest reduction seen in the patient population older than 80 years.¹²

Although the COVID-19 pandemic has been observed to impact MMS practice, patient perceptions, and clinical outcomes, it is unknown how the COVID-19 pandemic and corresponding rapidly evolving recommendations in dermatologic surgery have impacted the characteristics of cutaneous tumors treated by MMS.

Our study sought to determine the characteristics of skin cancers treated by MMS during the peak of government-mandated medical practice restrictions and business shutdowns in response to the COVID-19 pandemic and to compare them with characteristics of skin cancers treated during a prepandemic control period.

Methods

A retrospective chart review was conducted with approval from our institutional review board at the University of Texas Medical Branch (Galveston, Texas). Included in the chart review were all cutaneous malignancies treated by MMS at our outpatient, office-based surgical center from March 15, 2020, to April 30, 2020; this period corresponded to the peak of the COVID-19–related government-mandated medical and business shutdowns in our geographic region (southeast Texas). All cases performed were in compliance with national- and state-level guidance. Data were also collected for all cutaneous malignancies treated by MMS at our office from March 15, 2019, to April 30, 2019, as well as March 15, 2018, to April 30, 2018; these periods represented prepandemic control periods.

Data were collected for 516 surgeries performed on 458 patients and included patient age, preoperative clinical size, postoperative defect size, number of Mohs stages to achieve clearance, MMS appropriate use criteria (AUC) location (categorized as high-, medium-, or low-risk tumor location),¹³ and tumor type (categorized as BCC, SCC, or MIS). All variables were examined for unusual or missing values. Five patients with rare tumor types were observed and removed from the data set.

Statistical Analysis—An a priori power analysis for a power set at 0.85 determined sample sizes of 105 per group. Bivariate analyses were performed to compare variables for patients undergoing MMS during the pandemic vs prepandemic periods. Continuous outcome variables—Mohs stages, preoperative size, postoperative size, and patient age—were categorized for the analysis. Preoperative tumor size was dichotomized, with less than 2 cm² as the referent category vs 2 cm² or greater, and postoperative defect size was dichotomized with less than 3.6 cm² as the referent category vs 3.6 cm² or greater. Mohs stage was dichotomized as 1 stage (referent) vs more than 1 stage, and patient age was dichotomized as younger than 65 years (referent) vs 65 years or older.

Multivariate analyses were also performed to compare preoperative and postoperative sizes for patients undergoing MMS during the pandemic vs prepandemic periods, controlling for Mohs AUC location. Bivariate unadjusted and multivariate analyses were performed using a GENMOD logistic regression procedure in SAS (SAS Institute) to account for correlation in clustered data because a patient could be included for more than 1 surgery in the data set. Data were analyzed using SAS 9.4 for Windows. Because outcome variables tended to be skewed and not distributed normally, outcome variables were recorded as medians with interquartile ranges where possible to give a more accurate representation of the data than could be demonstrated with means with standard deviations.

Results

One hundred thirty-eight skin cancers were treated during the COVID-19 pandemic from March 15, 2020, to April 30, 2020, and 378 skin cancers were treated during the prepandemic control periods of March 15, 2019, to April 30, 2019, and March 15, 2018, to April 30, 2018. Tumor type treated during the pandemic period was more likely to be SCC or MIS (representing generally more severe tumor types) vs BCC when compared with the prepandemic periods, with an odds ratio (OR) of 1.763 (95% CI, 1.17-2.66). This outcome was statistically significant (P=.01).

Tumors treated during the pandemic period were more likely to have necessitated more than one Mohs stage for clearance compared to the prepandemic periods, though this difference was not statistically significant (OR, 1.461; 95% CI, 0.97-2.19; P=.056). Neither AUC location of treated tumors nor age were significantly different between prepandemic and pandemic periods (P=.58 and P=.84, respectively). Table 1 includes all bivariate analysis results.

Additionally, although mean preoperative and postoperative sizes were larger for each AUC location during the pandemic vs prepandemic periods, these differences did not reach statistical significance on multivariate analysis (P=.71 and P=.50, respectively)(Table 2).

Our practice has followed best practice guidelines dictated by our governing professional societies during the COVID-19 pandemic in the treatment of skin cancers by MMS, specifically highly symptomatic BCCs (in accordance with ACMS guidance), SCCs with high-risk features (in accordance with AAD, ACMS, and TDS guidance), and tumors with high risk for progression and metastasis such as melanomas (in accordance with TDS guidance). Melanoma in situ was also treated during the COVID-19 pandemic in accordance with the latter TDS guidance, particularly in light of the potential for upstaging to melanoma following resection (a phenomenon demonstrated to occur in 5%–29% of biopsied MIS lesions).¹⁴

In following best practice guidelines, our results suggested tumors treated by MMS were more severe, as evidenced by a statistically significant higher proportion of SCC and MIS tumors (representing more severe tumor types) vs BCC when compared to the prepandemic period. Supporting this conclusion, we observed larger pretreatment and posttreatment tumor sizes for all AUC locations and more tumors necessitating 2 or more stages for clearance during the pandemic vs prepandemic periods, though these differences did not reach statistical significance. We postulate these findings may be attributed to allocation of finite medical resources to the treatment of larger and more aggressive skin cancers. Additionally, these findings may be explained, in part, by limitations on patient case load imposed by social distancing measures and governing body regulations in effect during the study period, including those put forth by the AAD, ACMS, and TDS. Of note, our practice observed no hospitalizations or 911 calls during the studied period. This suggests no allocation of precious hospital resources away from patients with COVID-19 in our treatment of high-risk skin cancers.

The changing characteristics of cutaneous tumors treated by MMS during the pandemic are of clinical relevance. Larger postoperative wound sizes as observed during the pandemic, albeit not statistically significant, presumably affect reconstructive decisions. With larger wounds tending to necessitate repair by techniques higher on the reconstructive ladder, greater patient morbidity and cost are expected.¹⁵ As the cost-effectiveness of dermatology services remains a critical issue, this is an area ripe for future follow-up research. Furthermore, our observation that tumors tended to necessitate 2 or more stages for clearance during the pandemic more often than prepandemic periods, though not statistically significant, presumably affected operating times. Longer operating times during the pandemic may be of importance when making clinical decisions for patients for whom limiting health care exposure may be of particular concern. With more SCC and MIS tumors being treated relative to BCCs during the pandemic, one might expect greater size and severity of the BCCs we observe in the proceeding months to years.

As the ongoing COVID-19 pandemic continues to impact the landscape of cutaneous oncology, the need for adaptability is imperative. With 3- and 6-month skin cancer treatment deferrals lapsed, uncertainty surrounds ideal management of existing and new skin cancers arising during the pandemic. This study adds to a growing body of literature elucidating the impact of the COVID-19 pandemic on MMS practice; however, further studies and a tincture of time are needed to guide future best practice standards.

Acknowledgment—The authors acknowledge Gwen Baillargeon, MS (Galveston, Texas), who was the statistician for this article.

The COVID-19 pandemic has brought about unprecedented changes and challenges to medical practice, including new public health measure legislation, local and national medical authority recommendations, nursing home and other ancillary health center protocols, and novel clinical decision-making considerations.^1-3 In July 2020, the American Academy of Dermatology (AAD) addressed the changing landscape in dermatologic surgery, in part, by publishing recommendations on practice protocols during the COVID-19 pandemic.⁴ The guidelines recommended deferred treatment of superficial basal cell carcinomas (BCCs) for 6 months and all other BCC subtypes for 3 to 6 months. Furthermore, the guidelines recommended deferring treatment of all actinic keratoses and squamous cell carcinomas (SCCs) in situ “for now.” Squamous cell carcinoma treatment was to be guided by prognostic variables, such as location, size, depth, differentiation, perineural or lymphovascular invasion, recurrence, and immunosuppression. The guidelines recommended melanoma in situ (MIS) treatment be deferred for 3 months and invasive melanoma with histologic clearance obtained on excisional biopsy for 3 months. Other general recommendations included triaging clinics, rebooking according to clinical priority, using telehealth where possible, screening patients for COVID-19 signs and symptoms, staggering appointment times, spacing patient chairs, limiting support persons to 1, removing possible sources of infection in the waiting room, ensuring all patients sanitized their hands on arrival, rationing personal protective equipment, considering N95 masks for periorificial surgery, and using dissolving sutures to minimize multiple presentations.⁴

The American College of Mohs Surgery (ACMS), with guidance from its sister societies and the National Comprehensive Cancer Network, also communicated COVID-19–related recommendations to its members via intermittent newsletters during the initial peak of the pandemic in March and June 2020.⁵ General social distancing and office recommendations were similar to those released by the AAD. Recommendations for skin cancer treatment included deferring all BCCs for up to 3 months, with exceptions for highly symptomatic cancers and those with potential for substantial rapid growth. Squamous cell carcinoma in situ and small, well-differentiated SCCs were deferred, with priority placed on SCCs that were rapidly enlarging, poorly differentiated, demonstrated perineural invasion, were ulcerated, or were symptomatic. Patients with major risk factors were prioritized for treatment. Melanoma in situ was deferred for 2 to 3 months.⁵

State-level guidance from the Texas Dermatological Society (TDS) communicated in April 2020 stated that skin cancers with a potential for rapid progression and metastasis, such as melanoma and SCC, may require treatment as determined by the physician.⁶ The potential risk of serious adverse medical outcomes from not treating these cancers should be carefully documented. General practice measures for preventing the spread of COVID-19 were also recommended.⁶

In the setting of emerging novel recommendations, the practice of Mohs micrographic surgery (MMS) was notably impacted by the COVID-19 pandemic. According to one survey study from the United Kingdom conducted in April and May 2020, 49% of MMS services ceased and 36% were reduced during the infancy of the COVID-19 pandemic.⁷ Mohs micrographic surgery was largely suspended because of a lack of personal protective equipment and safety concerns, according to respondents. Additionally, respondents reported 77% of departments experienced redeployment of physicians and nurses to intensive care and medical wards. Thirty-five percent reported a reduction in the proportion of flaps/grafts to primary closures performed, 74% reported a decrease in outside referrals for repair by other specialties, 81% reported increased usage of dissolvable sutures, and 29% reported an increase in prophylactic antibiotic prescriptions.⁷ Another study from Italy reported a 46.5% reduction in dermatologic surgeries performed during the initial lockdown of the COVID-19 pandemic. Patients canceled 52.9% of procedures, and 12.5% were cancelled because of confirmed or suspected COVID-19 infection.⁸ Patient perceptions of MMS have also been impacted by the COVID-19 pandemic. According to a survey study of patients in the United Kingdom undergoing MMS during the pandemic, 47% were worried the hospital would cancel their surgery, 54% were anxious about using public transportation to attend their appointment, 30% were concerned about transmitting COVID-19 to household or family members, and 19% were worried about their ability to socially distance in the hospital.⁹

Evidence is also emerging that suggests the potential negative impact of the COVID-19 pandemic on morbidity and mortality outcomes in patients with skin cancer. One European study found an increase in Breslow thickness in primary melanomas diagnosed following the initial COVID-19 lockdown (0.88-mm average thickness prelockdown vs 1.96-mm average thickness postlockdown).¹⁰ An Italian study observed similar results—an increase in median Breslow thickness during the initial COVID-19 lockdown period of 0.5 mm from 0.4 mm during the prelockdown time period.¹¹ Also providing evidence for potentially poor patient outcomes, one study modeled the impact of backlog in cutaneous melanoma referrals in the United Kingdom on patient survival and predicted 138 attributable lives lost for a 1-month delay and 1171 lives lost for a 6-month delay. The model further predicted a 3.1% to 12.5% reduction in 10-year net survival incurred from a 3-month delay in melanoma treatment, with the largest reduction seen in the patient population older than 80 years.¹²

Although the COVID-19 pandemic has been observed to impact MMS practice, patient perceptions, and clinical outcomes, it is unknown how the COVID-19 pandemic and corresponding rapidly evolving recommendations in dermatologic surgery have impacted the characteristics of cutaneous tumors treated by MMS.

Our study sought to determine the characteristics of skin cancers treated by MMS during the peak of government-mandated medical practice restrictions and business shutdowns in response to the COVID-19 pandemic and to compare them with characteristics of skin cancers treated during a prepandemic control period.

Methods

A retrospective chart review was conducted with approval from our institutional review board at the University of Texas Medical Branch (Galveston, Texas). Included in the chart review were all cutaneous malignancies treated by MMS at our outpatient, office-based surgical center from March 15, 2020, to April 30, 2020; this period corresponded to the peak of the COVID-19–related government-mandated medical and business shutdowns in our geographic region (southeast Texas). All cases performed were in compliance with national- and state-level guidance. Data were also collected for all cutaneous malignancies treated by MMS at our office from March 15, 2019, to April 30, 2019, as well as March 15, 2018, to April 30, 2018; these periods represented prepandemic control periods.

Data were collected for 516 surgeries performed on 458 patients and included patient age, preoperative clinical size, postoperative defect size, number of Mohs stages to achieve clearance, MMS appropriate use criteria (AUC) location (categorized as high-, medium-, or low-risk tumor location),¹³ and tumor type (categorized as BCC, SCC, or MIS). All variables were examined for unusual or missing values. Five patients with rare tumor types were observed and removed from the data set.

Statistical Analysis—An a priori power analysis for a power set at 0.85 determined sample sizes of 105 per group. Bivariate analyses were performed to compare variables for patients undergoing MMS during the pandemic vs prepandemic periods. Continuous outcome variables—Mohs stages, preoperative size, postoperative size, and patient age—were categorized for the analysis. Preoperative tumor size was dichotomized, with less than 2 cm² as the referent category vs 2 cm² or greater, and postoperative defect size was dichotomized with less than 3.6 cm² as the referent category vs 3.6 cm² or greater. Mohs stage was dichotomized as 1 stage (referent) vs more than 1 stage, and patient age was dichotomized as younger than 65 years (referent) vs 65 years or older.

Multivariate analyses were also performed to compare preoperative and postoperative sizes for patients undergoing MMS during the pandemic vs prepandemic periods, controlling for Mohs AUC location. Bivariate unadjusted and multivariate analyses were performed using a GENMOD logistic regression procedure in SAS (SAS Institute) to account for correlation in clustered data because a patient could be included for more than 1 surgery in the data set. Data were analyzed using SAS 9.4 for Windows. Because outcome variables tended to be skewed and not distributed normally, outcome variables were recorded as medians with interquartile ranges where possible to give a more accurate representation of the data than could be demonstrated with means with standard deviations.

Results

One hundred thirty-eight skin cancers were treated during the COVID-19 pandemic from March 15, 2020, to April 30, 2020, and 378 skin cancers were treated during the prepandemic control periods of March 15, 2019, to April 30, 2019, and March 15, 2018, to April 30, 2018. Tumor type treated during the pandemic period was more likely to be SCC or MIS (representing generally more severe tumor types) vs BCC when compared with the prepandemic periods, with an odds ratio (OR) of 1.763 (95% CI, 1.17-2.66). This outcome was statistically significant (P=.01).

Tumors treated during the pandemic period were more likely to have necessitated more than one Mohs stage for clearance compared to the prepandemic periods, though this difference was not statistically significant (OR, 1.461; 95% CI, 0.97-2.19; P=.056). Neither AUC location of treated tumors nor age were significantly different between prepandemic and pandemic periods (P=.58 and P=.84, respectively). Table 1 includes all bivariate analysis results.

Additionally, although mean preoperative and postoperative sizes were larger for each AUC location during the pandemic vs prepandemic periods, these differences did not reach statistical significance on multivariate analysis (P=.71 and P=.50, respectively)(Table 2).

Our practice has followed best practice guidelines dictated by our governing professional societies during the COVID-19 pandemic in the treatment of skin cancers by MMS, specifically highly symptomatic BCCs (in accordance with ACMS guidance), SCCs with high-risk features (in accordance with AAD, ACMS, and TDS guidance), and tumors with high risk for progression and metastasis such as melanomas (in accordance with TDS guidance). Melanoma in situ was also treated during the COVID-19 pandemic in accordance with the latter TDS guidance, particularly in light of the potential for upstaging to melanoma following resection (a phenomenon demonstrated to occur in 5%–29% of biopsied MIS lesions).¹⁴

In following best practice guidelines, our results suggested tumors treated by MMS were more severe, as evidenced by a statistically significant higher proportion of SCC and MIS tumors (representing more severe tumor types) vs BCC when compared to the prepandemic period. Supporting this conclusion, we observed larger pretreatment and posttreatment tumor sizes for all AUC locations and more tumors necessitating 2 or more stages for clearance during the pandemic vs prepandemic periods, though these differences did not reach statistical significance. We postulate these findings may be attributed to allocation of finite medical resources to the treatment of larger and more aggressive skin cancers. Additionally, these findings may be explained, in part, by limitations on patient case load imposed by social distancing measures and governing body regulations in effect during the study period, including those put forth by the AAD, ACMS, and TDS. Of note, our practice observed no hospitalizations or 911 calls during the studied period. This suggests no allocation of precious hospital resources away from patients with COVID-19 in our treatment of high-risk skin cancers.

The changing characteristics of cutaneous tumors treated by MMS during the pandemic are of clinical relevance. Larger postoperative wound sizes as observed during the pandemic, albeit not statistically significant, presumably affect reconstructive decisions. With larger wounds tending to necessitate repair by techniques higher on the reconstructive ladder, greater patient morbidity and cost are expected.¹⁵ As the cost-effectiveness of dermatology services remains a critical issue, this is an area ripe for future follow-up research. Furthermore, our observation that tumors tended to necessitate 2 or more stages for clearance during the pandemic more often than prepandemic periods, though not statistically significant, presumably affected operating times. Longer operating times during the pandemic may be of importance when making clinical decisions for patients for whom limiting health care exposure may be of particular concern. With more SCC and MIS tumors being treated relative to BCCs during the pandemic, one might expect greater size and severity of the BCCs we observe in the proceeding months to years.

As the ongoing COVID-19 pandemic continues to impact the landscape of cutaneous oncology, the need for adaptability is imperative. With 3- and 6-month skin cancer treatment deferrals lapsed, uncertainty surrounds ideal management of existing and new skin cancers arising during the pandemic. This study adds to a growing body of literature elucidating the impact of the COVID-19 pandemic on MMS practice; however, further studies and a tincture of time are needed to guide future best practice standards.

Acknowledgment—The authors acknowledge Gwen Baillargeon, MS (Galveston, Texas), who was the statistician for this article.

The COVID-19 pandemic has brought about unprecedented changes and challenges to medical practice, including new public health measure legislation, local and national medical authority recommendations, nursing home and other ancillary health center protocols, and novel clinical decision-making considerations.^1-3 In July 2020, the American Academy of Dermatology (AAD) addressed the changing landscape in dermatologic surgery, in part, by publishing recommendations on practice protocols during the COVID-19 pandemic.⁴ The guidelines recommended deferred treatment of superficial basal cell carcinomas (BCCs) for 6 months and all other BCC subtypes for 3 to 6 months. Furthermore, the guidelines recommended deferring treatment of all actinic keratoses and squamous cell carcinomas (SCCs) in situ “for now.” Squamous cell carcinoma treatment was to be guided by prognostic variables, such as location, size, depth, differentiation, perineural or lymphovascular invasion, recurrence, and immunosuppression. The guidelines recommended melanoma in situ (MIS) treatment be deferred for 3 months and invasive melanoma with histologic clearance obtained on excisional biopsy for 3 months. Other general recommendations included triaging clinics, rebooking according to clinical priority, using telehealth where possible, screening patients for COVID-19 signs and symptoms, staggering appointment times, spacing patient chairs, limiting support persons to 1, removing possible sources of infection in the waiting room, ensuring all patients sanitized their hands on arrival, rationing personal protective equipment, considering N95 masks for periorificial surgery, and using dissolving sutures to minimize multiple presentations.⁴

The American College of Mohs Surgery (ACMS), with guidance from its sister societies and the National Comprehensive Cancer Network, also communicated COVID-19–related recommendations to its members via intermittent newsletters during the initial peak of the pandemic in March and June 2020.⁵ General social distancing and office recommendations were similar to those released by the AAD. Recommendations for skin cancer treatment included deferring all BCCs for up to 3 months, with exceptions for highly symptomatic cancers and those with potential for substantial rapid growth. Squamous cell carcinoma in situ and small, well-differentiated SCCs were deferred, with priority placed on SCCs that were rapidly enlarging, poorly differentiated, demonstrated perineural invasion, were ulcerated, or were symptomatic. Patients with major risk factors were prioritized for treatment. Melanoma in situ was deferred for 2 to 3 months.⁵

State-level guidance from the Texas Dermatological Society (TDS) communicated in April 2020 stated that skin cancers with a potential for rapid progression and metastasis, such as melanoma and SCC, may require treatment as determined by the physician.⁶ The potential risk of serious adverse medical outcomes from not treating these cancers should be carefully documented. General practice measures for preventing the spread of COVID-19 were also recommended.⁶

In the setting of emerging novel recommendations, the practice of Mohs micrographic surgery (MMS) was notably impacted by the COVID-19 pandemic. According to one survey study from the United Kingdom conducted in April and May 2020, 49% of MMS services ceased and 36% were reduced during the infancy of the COVID-19 pandemic.⁷ Mohs micrographic surgery was largely suspended because of a lack of personal protective equipment and safety concerns, according to respondents. Additionally, respondents reported 77% of departments experienced redeployment of physicians and nurses to intensive care and medical wards. Thirty-five percent reported a reduction in the proportion of flaps/grafts to primary closures performed, 74% reported a decrease in outside referrals for repair by other specialties, 81% reported increased usage of dissolvable sutures, and 29% reported an increase in prophylactic antibiotic prescriptions.⁷ Another study from Italy reported a 46.5% reduction in dermatologic surgeries performed during the initial lockdown of the COVID-19 pandemic. Patients canceled 52.9% of procedures, and 12.5% were cancelled because of confirmed or suspected COVID-19 infection.⁸ Patient perceptions of MMS have also been impacted by the COVID-19 pandemic. According to a survey study of patients in the United Kingdom undergoing MMS during the pandemic, 47% were worried the hospital would cancel their surgery, 54% were anxious about using public transportation to attend their appointment, 30% were concerned about transmitting COVID-19 to household or family members, and 19% were worried about their ability to socially distance in the hospital.⁹

Evidence is also emerging that suggests the potential negative impact of the COVID-19 pandemic on morbidity and mortality outcomes in patients with skin cancer. One European study found an increase in Breslow thickness in primary melanomas diagnosed following the initial COVID-19 lockdown (0.88-mm average thickness prelockdown vs 1.96-mm average thickness postlockdown).¹⁰ An Italian study observed similar results—an increase in median Breslow thickness during the initial COVID-19 lockdown period of 0.5 mm from 0.4 mm during the prelockdown time period.¹¹ Also providing evidence for potentially poor patient outcomes, one study modeled the impact of backlog in cutaneous melanoma referrals in the United Kingdom on patient survival and predicted 138 attributable lives lost for a 1-month delay and 1171 lives lost for a 6-month delay. The model further predicted a 3.1% to 12.5% reduction in 10-year net survival incurred from a 3-month delay in melanoma treatment, with the largest reduction seen in the patient population older than 80 years.¹²

Although the COVID-19 pandemic has been observed to impact MMS practice, patient perceptions, and clinical outcomes, it is unknown how the COVID-19 pandemic and corresponding rapidly evolving recommendations in dermatologic surgery have impacted the characteristics of cutaneous tumors treated by MMS.

Our study sought to determine the characteristics of skin cancers treated by MMS during the peak of government-mandated medical practice restrictions and business shutdowns in response to the COVID-19 pandemic and to compare them with characteristics of skin cancers treated during a prepandemic control period.

Methods

A retrospective chart review was conducted with approval from our institutional review board at the University of Texas Medical Branch (Galveston, Texas). Included in the chart review were all cutaneous malignancies treated by MMS at our outpatient, office-based surgical center from March 15, 2020, to April 30, 2020; this period corresponded to the peak of the COVID-19–related government-mandated medical and business shutdowns in our geographic region (southeast Texas). All cases performed were in compliance with national- and state-level guidance. Data were also collected for all cutaneous malignancies treated by MMS at our office from March 15, 2019, to April 30, 2019, as well as March 15, 2018, to April 30, 2018; these periods represented prepandemic control periods.

Data were collected for 516 surgeries performed on 458 patients and included patient age, preoperative clinical size, postoperative defect size, number of Mohs stages to achieve clearance, MMS appropriate use criteria (AUC) location (categorized as high-, medium-, or low-risk tumor location),¹³ and tumor type (categorized as BCC, SCC, or MIS). All variables were examined for unusual or missing values. Five patients with rare tumor types were observed and removed from the data set.

Statistical Analysis—An a priori power analysis for a power set at 0.85 determined sample sizes of 105 per group. Bivariate analyses were performed to compare variables for patients undergoing MMS during the pandemic vs prepandemic periods. Continuous outcome variables—Mohs stages, preoperative size, postoperative size, and patient age—were categorized for the analysis. Preoperative tumor size was dichotomized, with less than 2 cm² as the referent category vs 2 cm² or greater, and postoperative defect size was dichotomized with less than 3.6 cm² as the referent category vs 3.6 cm² or greater. Mohs stage was dichotomized as 1 stage (referent) vs more than 1 stage, and patient age was dichotomized as younger than 65 years (referent) vs 65 years or older.

Multivariate analyses were also performed to compare preoperative and postoperative sizes for patients undergoing MMS during the pandemic vs prepandemic periods, controlling for Mohs AUC location. Bivariate unadjusted and multivariate analyses were performed using a GENMOD logistic regression procedure in SAS (SAS Institute) to account for correlation in clustered data because a patient could be included for more than 1 surgery in the data set. Data were analyzed using SAS 9.4 for Windows. Because outcome variables tended to be skewed and not distributed normally, outcome variables were recorded as medians with interquartile ranges where possible to give a more accurate representation of the data than could be demonstrated with means with standard deviations.

Results

One hundred thirty-eight skin cancers were treated during the COVID-19 pandemic from March 15, 2020, to April 30, 2020, and 378 skin cancers were treated during the prepandemic control periods of March 15, 2019, to April 30, 2019, and March 15, 2018, to April 30, 2018. Tumor type treated during the pandemic period was more likely to be SCC or MIS (representing generally more severe tumor types) vs BCC when compared with the prepandemic periods, with an odds ratio (OR) of 1.763 (95% CI, 1.17-2.66). This outcome was statistically significant (P=.01).

Tumors treated during the pandemic period were more likely to have necessitated more than one Mohs stage for clearance compared to the prepandemic periods, though this difference was not statistically significant (OR, 1.461; 95% CI, 0.97-2.19; P=.056). Neither AUC location of treated tumors nor age were significantly different between prepandemic and pandemic periods (P=.58 and P=.84, respectively). Table 1 includes all bivariate analysis results.

Additionally, although mean preoperative and postoperative sizes were larger for each AUC location during the pandemic vs prepandemic periods, these differences did not reach statistical significance on multivariate analysis (P=.71 and P=.50, respectively)(Table 2).

Our practice has followed best practice guidelines dictated by our governing professional societies during the COVID-19 pandemic in the treatment of skin cancers by MMS, specifically highly symptomatic BCCs (in accordance with ACMS guidance), SCCs with high-risk features (in accordance with AAD, ACMS, and TDS guidance), and tumors with high risk for progression and metastasis such as melanomas (in accordance with TDS guidance). Melanoma in situ was also treated during the COVID-19 pandemic in accordance with the latter TDS guidance, particularly in light of the potential for upstaging to melanoma following resection (a phenomenon demonstrated to occur in 5%–29% of biopsied MIS lesions).¹⁴

In following best practice guidelines, our results suggested tumors treated by MMS were more severe, as evidenced by a statistically significant higher proportion of SCC and MIS tumors (representing more severe tumor types) vs BCC when compared to the prepandemic period. Supporting this conclusion, we observed larger pretreatment and posttreatment tumor sizes for all AUC locations and more tumors necessitating 2 or more stages for clearance during the pandemic vs prepandemic periods, though these differences did not reach statistical significance. We postulate these findings may be attributed to allocation of finite medical resources to the treatment of larger and more aggressive skin cancers. Additionally, these findings may be explained, in part, by limitations on patient case load imposed by social distancing measures and governing body regulations in effect during the study period, including those put forth by the AAD, ACMS, and TDS. Of note, our practice observed no hospitalizations or 911 calls during the studied period. This suggests no allocation of precious hospital resources away from patients with COVID-19 in our treatment of high-risk skin cancers.

The changing characteristics of cutaneous tumors treated by MMS during the pandemic are of clinical relevance. Larger postoperative wound sizes as observed during the pandemic, albeit not statistically significant, presumably affect reconstructive decisions. With larger wounds tending to necessitate repair by techniques higher on the reconstructive ladder, greater patient morbidity and cost are expected.¹⁵ As the cost-effectiveness of dermatology services remains a critical issue, this is an area ripe for future follow-up research. Furthermore, our observation that tumors tended to necessitate 2 or more stages for clearance during the pandemic more often than prepandemic periods, though not statistically significant, presumably affected operating times. Longer operating times during the pandemic may be of importance when making clinical decisions for patients for whom limiting health care exposure may be of particular concern. With more SCC and MIS tumors being treated relative to BCCs during the pandemic, one might expect greater size and severity of the BCCs we observe in the proceeding months to years.

As the ongoing COVID-19 pandemic continues to impact the landscape of cutaneous oncology, the need for adaptability is imperative. With 3- and 6-month skin cancer treatment deferrals lapsed, uncertainty surrounds ideal management of existing and new skin cancers arising during the pandemic. This study adds to a growing body of literature elucidating the impact of the COVID-19 pandemic on MMS practice; however, further studies and a tincture of time are needed to guide future best practice standards.

Acknowledgment—The authors acknowledge Gwen Baillargeon, MS (Galveston, Texas), who was the statistician for this article.

Melanomas have been designated as small melanomas or micromelanomas according to their long-axis diameter (<6 mm and ≤3 mm, respectively).^1-3 Because small-diameter melanomas also have the potential to metastasize, particularly if nodular, early diagnosis can be highly rewarding. Deep melanomas with small diameters may have the same potential for metastasis as large-diameter melanomas. In this context, dermoscopy, digital dermoscopic monitoring, and total-body photography are useful in clinical practice. However, these techniques are of limited utility for small, dermoscopic feature–poor melanomas. Conversely, less than 10% of changing lesions, which are spotted via digital dermoscopic surveillance, turn out to be melanomas; therefore, simply removing all changing lesions may result in many unnecessary excisions of benign lesions.⁴

In vivo reflectance confocal microscopy (RCM) is an advanced technique that allows recognition of the architectural and cellular details of pigmented lesions. Reflectance confocal microscopy has the potential to reduce the rate of unnecessary excisions and to diminish the risk for missing a melanoma.^5-7 In meta-analyses, RCM sensitivity was reported as 90% to 93% and specificity was reported as 78% to 82% in detecting melanoma.^8,9

We describe a case that highlights the potential role of RCM in the diagnosis of small-diameter melanomas.

Case Report

A 57-year-old man with Fitzpatrick skin type III presented to the dermato-oncology unit for evaluation of multiple nevi. He was otherwise healthy and denied a history of skin cancer. Total-body skin examination with dermoscopy was performed, and several mildly atypical lesions were identified. We decided to perform digital dermoscopic monitoring. The patient’s 6-month monitoring appointment had been scheduled, but he did not arrive for the follow-up visit until 10 months after the initial examination. A lesion on the left arm, which initially was 1.5 mm in diameter, had enlarged. It was now a dark brown–gray papule with a 2.5-mm diameter (Figure 1). Dermoscopy revealed grayish globules/dots at the center of the lesion, reticular gray-blue areas, and few milialike cysts; at the periphery, a narrow rim of brownish delicate pigment network also was seen (Figure 2). The clinical and dermoscopic differential diagnosis was either an atypical nevus or an early melanoma. For a more precise diagnosis before excision, the lesion was evaluated with RCM, which takes 10 to 15 minutes to perform.

Under RCM at the epidermis level, there was a cobblestone pattern that showed a focus with mild disarrangement and few small, roundish, nucleated cells (Figure 3). A mosaic image, akin to low-magnification microscopy that enables overview of the entire lesion, at the level of the dermoepidermal junction (DEJ) showed an overall irregular meshwork pattern. Higher-magnification optical sections showed marked and diffuse (extending >10% of lesion area) architectural disorder with confluent junctional nests that were irregular to bizarre in shape and uneven in size and spacing as well as edged and nonedged papillae. At the superficial dermal level, atypical bright nucleated cells (>5 cells/mm²) were observed (Figure 4). Bright dots and/or plump bright cells within papillae also were observed. These RCM findings were highly suggestive for melanoma.

Histopathology showed an asymmetric, junctional, lentiginous, and nested proliferation of atypical epithelioid melanocytes, with few melanocytes in a pagetoid spread. There were small nests of atypical epithelioid melanocytes at the superficial dermis extending to a depth of 0.3 mm. The atypical epithelioid melanocytes displayed angulated hyperchromatic nuclei with conspicuous nucleoli and dusty brown cytoplasm. There was notable inflammation and pigment incontinence at the dermis. There was no evidence of ulceration or mitosis at the dermal component. The diagnosis of a pT1a malignant melanoma was reported (Figure 5).

Comment

A small but enlarging dark gray papule with reticular gray-blue areas under dermoscopy in a 57-year-old man is obviously suspicious for melanoma. In daily practice, this type of small-diameter melanoma is difficult to diagnose with high confidence. We balance our aim to diagnose melanomas early with the need to reduce unnecessary excisions. Reflectance confocal microscopy may allow the clinician to arrive at the correct diagnosis and management decision with confidence before excision of the lesion.

The distinction of a small-diameter melanoma from a nevus via RCM relies on evaluation of the architectural and cellular features. Findings on RCM in small-diameter melanomas have been scarcely reported in the literature; Pupelli et al¹⁰ evaluated small melanomas with a diameter of 2 to 5 mm. Among these small-diameter melanomas, the RCM features suggestive for melanomas were the presence of cytologic atypia with cellular pleomorphism, architectural disorder with irregular nests, at least 5 pagetoid cells/mm², dendrites or tangled lines (ie, short fine lines with no visible nucleus interlacing with the adjacent keratinocytes) within the epidermis, and atypical roundish cells at the DEJ.¹⁰

The distinction between an atypical nevus and a small-diameter melanoma using RCM occasionally may be challenging.¹¹ Pellacani et al¹² reported an algorithm to distinguish melanoma from atypical nevi. According to this algorithm, when at least 1 of the architectural atypia features (irregular junctional nests, short interconnections between junctional nests, and nonhomogeneous cellularity within junctional nests) and at least 1 of the cytologic atypia features (round pagetoid cells or atypical cells at the DEJ) are observed simultaneously, the lesion is diagnosed as a dysplastic nevus or a melanoma in the first step. In the second step, the RCM diagnosis of melanoma requires at least 1 of 3 parameters: roundish pagetoid cells encompassing at least 50% of the lesional area at the spinous layer, atypical cells involving at least 50% of the lesional area at the DEJ level, and nonedged papillae involving at least 10% of the lesional area.¹² Accordingly, our case corresponded with these RCM criteria for a melanoma, given that there were irregular junctional nests, atypical cells at the DEJ, and nonedged papillae involving at least 10% of the lesion.

The current limitations of RCM are the high cost of the device (approximately $58,125–$139,400 for different models), the amount of time needed to train staff in RCM units (seminars, congresses, and special courses organized by the International Confocal Working Group), and the amount of time needed for evaluation of individual lesions (15–20 minutes). However, RCM can be valuable in the clinical diagnosis of difficult lesions, as seen in our case.

Conclusion

Our case highlights the benefit of RCM in allowing the confident diagnosis and correct management of a small-diameter melanoma that turned out to be a melanoma with 0.3-mm Breslow thickness. Even so, histopathologic evaluation remains the gold standard for the diagnosis of melanoma.

Melanomas have been designated as small melanomas or micromelanomas according to their long-axis diameter (<6 mm and ≤3 mm, respectively).^1-3 Because small-diameter melanomas also have the potential to metastasize, particularly if nodular, early diagnosis can be highly rewarding. Deep melanomas with small diameters may have the same potential for metastasis as large-diameter melanomas. In this context, dermoscopy, digital dermoscopic monitoring, and total-body photography are useful in clinical practice. However, these techniques are of limited utility for small, dermoscopic feature–poor melanomas. Conversely, less than 10% of changing lesions, which are spotted via digital dermoscopic surveillance, turn out to be melanomas; therefore, simply removing all changing lesions may result in many unnecessary excisions of benign lesions.⁴

In vivo reflectance confocal microscopy (RCM) is an advanced technique that allows recognition of the architectural and cellular details of pigmented lesions. Reflectance confocal microscopy has the potential to reduce the rate of unnecessary excisions and to diminish the risk for missing a melanoma.^5-7 In meta-analyses, RCM sensitivity was reported as 90% to 93% and specificity was reported as 78% to 82% in detecting melanoma.^8,9

We describe a case that highlights the potential role of RCM in the diagnosis of small-diameter melanomas.

Case Report

A 57-year-old man with Fitzpatrick skin type III presented to the dermato-oncology unit for evaluation of multiple nevi. He was otherwise healthy and denied a history of skin cancer. Total-body skin examination with dermoscopy was performed, and several mildly atypical lesions were identified. We decided to perform digital dermoscopic monitoring. The patient’s 6-month monitoring appointment had been scheduled, but he did not arrive for the follow-up visit until 10 months after the initial examination. A lesion on the left arm, which initially was 1.5 mm in diameter, had enlarged. It was now a dark brown–gray papule with a 2.5-mm diameter (Figure 1). Dermoscopy revealed grayish globules/dots at the center of the lesion, reticular gray-blue areas, and few milialike cysts; at the periphery, a narrow rim of brownish delicate pigment network also was seen (Figure 2). The clinical and dermoscopic differential diagnosis was either an atypical nevus or an early melanoma. For a more precise diagnosis before excision, the lesion was evaluated with RCM, which takes 10 to 15 minutes to perform.

Under RCM at the epidermis level, there was a cobblestone pattern that showed a focus with mild disarrangement and few small, roundish, nucleated cells (Figure 3). A mosaic image, akin to low-magnification microscopy that enables overview of the entire lesion, at the level of the dermoepidermal junction (DEJ) showed an overall irregular meshwork pattern. Higher-magnification optical sections showed marked and diffuse (extending >10% of lesion area) architectural disorder with confluent junctional nests that were irregular to bizarre in shape and uneven in size and spacing as well as edged and nonedged papillae. At the superficial dermal level, atypical bright nucleated cells (>5 cells/mm²) were observed (Figure 4). Bright dots and/or plump bright cells within papillae also were observed. These RCM findings were highly suggestive for melanoma.

Histopathology showed an asymmetric, junctional, lentiginous, and nested proliferation of atypical epithelioid melanocytes, with few melanocytes in a pagetoid spread. There were small nests of atypical epithelioid melanocytes at the superficial dermis extending to a depth of 0.3 mm. The atypical epithelioid melanocytes displayed angulated hyperchromatic nuclei with conspicuous nucleoli and dusty brown cytoplasm. There was notable inflammation and pigment incontinence at the dermis. There was no evidence of ulceration or mitosis at the dermal component. The diagnosis of a pT1a malignant melanoma was reported (Figure 5).

Comment

A small but enlarging dark gray papule with reticular gray-blue areas under dermoscopy in a 57-year-old man is obviously suspicious for melanoma. In daily practice, this type of small-diameter melanoma is difficult to diagnose with high confidence. We balance our aim to diagnose melanomas early with the need to reduce unnecessary excisions. Reflectance confocal microscopy may allow the clinician to arrive at the correct diagnosis and management decision with confidence before excision of the lesion.

The distinction of a small-diameter melanoma from a nevus via RCM relies on evaluation of the architectural and cellular features. Findings on RCM in small-diameter melanomas have been scarcely reported in the literature; Pupelli et al¹⁰ evaluated small melanomas with a diameter of 2 to 5 mm. Among these small-diameter melanomas, the RCM features suggestive for melanomas were the presence of cytologic atypia with cellular pleomorphism, architectural disorder with irregular nests, at least 5 pagetoid cells/mm², dendrites or tangled lines (ie, short fine lines with no visible nucleus interlacing with the adjacent keratinocytes) within the epidermis, and atypical roundish cells at the DEJ.¹⁰

The distinction between an atypical nevus and a small-diameter melanoma using RCM occasionally may be challenging.¹¹ Pellacani et al¹² reported an algorithm to distinguish melanoma from atypical nevi. According to this algorithm, when at least 1 of the architectural atypia features (irregular junctional nests, short interconnections between junctional nests, and nonhomogeneous cellularity within junctional nests) and at least 1 of the cytologic atypia features (round pagetoid cells or atypical cells at the DEJ) are observed simultaneously, the lesion is diagnosed as a dysplastic nevus or a melanoma in the first step. In the second step, the RCM diagnosis of melanoma requires at least 1 of 3 parameters: roundish pagetoid cells encompassing at least 50% of the lesional area at the spinous layer, atypical cells involving at least 50% of the lesional area at the DEJ level, and nonedged papillae involving at least 10% of the lesional area.¹² Accordingly, our case corresponded with these RCM criteria for a melanoma, given that there were irregular junctional nests, atypical cells at the DEJ, and nonedged papillae involving at least 10% of the lesion.

The current limitations of RCM are the high cost of the device (approximately $58,125–$139,400 for different models), the amount of time needed to train staff in RCM units (seminars, congresses, and special courses organized by the International Confocal Working Group), and the amount of time needed for evaluation of individual lesions (15–20 minutes). However, RCM can be valuable in the clinical diagnosis of difficult lesions, as seen in our case.

Conclusion

Our case highlights the benefit of RCM in allowing the confident diagnosis and correct management of a small-diameter melanoma that turned out to be a melanoma with 0.3-mm Breslow thickness. Even so, histopathologic evaluation remains the gold standard for the diagnosis of melanoma.

Melanomas have been designated as small melanomas or micromelanomas according to their long-axis diameter (<6 mm and ≤3 mm, respectively).^1-3 Because small-diameter melanomas also have the potential to metastasize, particularly if nodular, early diagnosis can be highly rewarding. Deep melanomas with small diameters may have the same potential for metastasis as large-diameter melanomas. In this context, dermoscopy, digital dermoscopic monitoring, and total-body photography are useful in clinical practice. However, these techniques are of limited utility for small, dermoscopic feature–poor melanomas. Conversely, less than 10% of changing lesions, which are spotted via digital dermoscopic surveillance, turn out to be melanomas; therefore, simply removing all changing lesions may result in many unnecessary excisions of benign lesions.⁴

In vivo reflectance confocal microscopy (RCM) is an advanced technique that allows recognition of the architectural and cellular details of pigmented lesions. Reflectance confocal microscopy has the potential to reduce the rate of unnecessary excisions and to diminish the risk for missing a melanoma.^5-7 In meta-analyses, RCM sensitivity was reported as 90% to 93% and specificity was reported as 78% to 82% in detecting melanoma.^8,9

We describe a case that highlights the potential role of RCM in the diagnosis of small-diameter melanomas.

Case Report

A 57-year-old man with Fitzpatrick skin type III presented to the dermato-oncology unit for evaluation of multiple nevi. He was otherwise healthy and denied a history of skin cancer. Total-body skin examination with dermoscopy was performed, and several mildly atypical lesions were identified. We decided to perform digital dermoscopic monitoring. The patient’s 6-month monitoring appointment had been scheduled, but he did not arrive for the follow-up visit until 10 months after the initial examination. A lesion on the left arm, which initially was 1.5 mm in diameter, had enlarged. It was now a dark brown–gray papule with a 2.5-mm diameter (Figure 1). Dermoscopy revealed grayish globules/dots at the center of the lesion, reticular gray-blue areas, and few milialike cysts; at the periphery, a narrow rim of brownish delicate pigment network also was seen (Figure 2). The clinical and dermoscopic differential diagnosis was either an atypical nevus or an early melanoma. For a more precise diagnosis before excision, the lesion was evaluated with RCM, which takes 10 to 15 minutes to perform.

Under RCM at the epidermis level, there was a cobblestone pattern that showed a focus with mild disarrangement and few small, roundish, nucleated cells (Figure 3). A mosaic image, akin to low-magnification microscopy that enables overview of the entire lesion, at the level of the dermoepidermal junction (DEJ) showed an overall irregular meshwork pattern. Higher-magnification optical sections showed marked and diffuse (extending >10% of lesion area) architectural disorder with confluent junctional nests that were irregular to bizarre in shape and uneven in size and spacing as well as edged and nonedged papillae. At the superficial dermal level, atypical bright nucleated cells (>5 cells/mm²) were observed (Figure 4). Bright dots and/or plump bright cells within papillae also were observed. These RCM findings were highly suggestive for melanoma.

Histopathology showed an asymmetric, junctional, lentiginous, and nested proliferation of atypical epithelioid melanocytes, with few melanocytes in a pagetoid spread. There were small nests of atypical epithelioid melanocytes at the superficial dermis extending to a depth of 0.3 mm. The atypical epithelioid melanocytes displayed angulated hyperchromatic nuclei with conspicuous nucleoli and dusty brown cytoplasm. There was notable inflammation and pigment incontinence at the dermis. There was no evidence of ulceration or mitosis at the dermal component. The diagnosis of a pT1a malignant melanoma was reported (Figure 5).

Comment

A small but enlarging dark gray papule with reticular gray-blue areas under dermoscopy in a 57-year-old man is obviously suspicious for melanoma. In daily practice, this type of small-diameter melanoma is difficult to diagnose with high confidence. We balance our aim to diagnose melanomas early with the need to reduce unnecessary excisions. Reflectance confocal microscopy may allow the clinician to arrive at the correct diagnosis and management decision with confidence before excision of the lesion.

The distinction of a small-diameter melanoma from a nevus via RCM relies on evaluation of the architectural and cellular features. Findings on RCM in small-diameter melanomas have been scarcely reported in the literature; Pupelli et al¹⁰ evaluated small melanomas with a diameter of 2 to 5 mm. Among these small-diameter melanomas, the RCM features suggestive for melanomas were the presence of cytologic atypia with cellular pleomorphism, architectural disorder with irregular nests, at least 5 pagetoid cells/mm², dendrites or tangled lines (ie, short fine lines with no visible nucleus interlacing with the adjacent keratinocytes) within the epidermis, and atypical roundish cells at the DEJ.¹⁰

The distinction between an atypical nevus and a small-diameter melanoma using RCM occasionally may be challenging.¹¹ Pellacani et al¹² reported an algorithm to distinguish melanoma from atypical nevi. According to this algorithm, when at least 1 of the architectural atypia features (irregular junctional nests, short interconnections between junctional nests, and nonhomogeneous cellularity within junctional nests) and at least 1 of the cytologic atypia features (round pagetoid cells or atypical cells at the DEJ) are observed simultaneously, the lesion is diagnosed as a dysplastic nevus or a melanoma in the first step. In the second step, the RCM diagnosis of melanoma requires at least 1 of 3 parameters: roundish pagetoid cells encompassing at least 50% of the lesional area at the spinous layer, atypical cells involving at least 50% of the lesional area at the DEJ level, and nonedged papillae involving at least 10% of the lesional area.¹² Accordingly, our case corresponded with these RCM criteria for a melanoma, given that there were irregular junctional nests, atypical cells at the DEJ, and nonedged papillae involving at least 10% of the lesion.

The current limitations of RCM are the high cost of the device (approximately $58,125–$139,400 for different models), the amount of time needed to train staff in RCM units (seminars, congresses, and special courses organized by the International Confocal Working Group), and the amount of time needed for evaluation of individual lesions (15–20 minutes). However, RCM can be valuable in the clinical diagnosis of difficult lesions, as seen in our case.

Conclusion

Our case highlights the benefit of RCM in allowing the confident diagnosis and correct management of a small-diameter melanoma that turned out to be a melanoma with 0.3-mm Breslow thickness. Even so, histopathologic evaluation remains the gold standard for the diagnosis of melanoma.