Dermatology

A registry-based study provides further evidence that treatment with dupilumab significantly reduces severity and symptoms of atopic dermatitis (AD) in clinical practice.

Dupilumab also decreased severity-associated biomarkers in pediatric patients with moderate to severe AD, researchers in the Netherlands reported.

Obtaining serum biomarkers is not the current standard in everyday practice, but studying them may improve understanding of who might respond best to dupilumab, said Jessica Hui, MD, a pediatric allergist and immunologist at National Jewish Health in Denver, in an email comment to this news organization.

“AD is heterogeneous, as each patient may have different presentations and underlying biology,” said Dr. Hui, who wasn’t involved in the research. “Studying biomarkers can eventually assist us in providing targeted therapy to each individual patient.”

Dr. Hui added, “As blood biomarkers can inform us of severity and treatment response, we can be hopeful that this will assist us in the management of AD patients in the future.”
 

Examining effect on disease severity

Dupilumab, a monoclonal antibody that inhibits interleukin (IL)-4 and IL-13 signaling, is approved in Europe and the United States to treat moderate to severe AD in patients 6 months of age or older, and to treat certain other inflammatory conditions.

Phase 3 studies show that dupilumab is effective for improving AD symptoms and quality of life in pediatric patients, but few clinical practice studies have researched the effect of the therapy on severity- and disease-related biomarkers in this population, the study authors write.

The study was published online in Pediatric Allergy Immunology.

In a new study, a team led by Esmé Kamphuis, MD, of the University of Groningen, the Netherlands, and colleagues evaluated the efficacy and safety of a 28-week dupilumab treatment course in 61 pediatric patients with moderate to severe AD. Additionally, the investigators examined the effect of this treatment regimen on serum biomarkers associated with disease severity.

Patients in the study were registered in the multicenter BioDay registry, which includes patients with moderate to severe AD receiving biologics or small-molecule agents. The AD cohort included children between 6 and 12 years of age (n = 16) and adolescents between 12 and less than 18 years of age (n = 45), all of whom received dupilumab on a dosing regimen indicated by age and body weight.

Over one-third (36.1%) of dupilumab-treated patients achieved an Investigator Global Assessment score of “almost clear” by 28 weeks of treatment. Approximately 75.4% of patients reached an Eczema Area and Severity Index (EASI) of 50, 49.2% reached EASI-75, and 24.6% reached EASI-90 at the 7-month follow-up.

Among patient-reported outcomes, 84.7% experienced improvements of 4 or more points on the Patient-Oriented Eczema Measure after the 28-week dupilumab treatment. In addition, improvements of 4 or more points on the Numeric Rating Scale for pruritus and pain were achieved by 45.3% and 77.4% of patients, respectively.

The most frequently reported side effects included conjunctivitis (n = 10) and headache (n = 4).

Of the 19 severity-associated serum biomarkers measured at baseline, week 4, and week 16, markers related to AD severity and treatment response significantly decreased during treatment (thymus- and activation-regulated chemokine, pulmonary and activation-regulated chemokine, periostin, soluble IL-2 receptor alpha).

A predicted EASI, calculated from selected biomarkers, demonstrated a significant association with disease severity in the cohort.
 

Implications for practice

When asked to comment on the study findings, Raegan Hunt, MD, the division chief of pediatric dermatology at Texas Children’s Hospital in Houston, said it is important to validate the changes in AD serum biomarkers in pediatric patients on dupilumab therapy, given that this treatment has historically been better studied in adults.

“This study adds to daily practice outcomes data, which in many cases is more relevant to the everyday care of patients than structured clinical trial data,” said Dr. Hunt, an associate professor at the Baylor College of Medicine, Houston.

Dr. Hunt, who didn’t participate in the study, noted that more research is needed on the adverse effects of dupilumab in the pediatric AD population.

Dr. Hui added that there is a lack of clear understanding of the exact underlying mechanisms for certain side effects, such as conjunctivitis, warranting further study.

The study’s BioDay registry is funded by Sanofi/Regeneron, AbbVie, Leo Pharma, Pfizer, and Eli Lilly. Several study coauthors report relationships with several pharmaceutical companies. Dr. Hunt and Dr. Hui report no relevant financial relationships.

A version of this article first appeared on Medscape.com.

A registry-based study provides further evidence that treatment with dupilumab significantly reduces severity and symptoms of atopic dermatitis (AD) in clinical practice.

Dupilumab also decreased severity-associated biomarkers in pediatric patients with moderate to severe AD, researchers in the Netherlands reported.

Obtaining serum biomarkers is not the current standard in everyday practice, but studying them may improve understanding of who might respond best to dupilumab, said Jessica Hui, MD, a pediatric allergist and immunologist at National Jewish Health in Denver, in an email comment to this news organization.

“AD is heterogeneous, as each patient may have different presentations and underlying biology,” said Dr. Hui, who wasn’t involved in the research. “Studying biomarkers can eventually assist us in providing targeted therapy to each individual patient.”

Dr. Hui added, “As blood biomarkers can inform us of severity and treatment response, we can be hopeful that this will assist us in the management of AD patients in the future.”
 

Examining effect on disease severity

Dupilumab, a monoclonal antibody that inhibits interleukin (IL)-4 and IL-13 signaling, is approved in Europe and the United States to treat moderate to severe AD in patients 6 months of age or older, and to treat certain other inflammatory conditions.

Phase 3 studies show that dupilumab is effective for improving AD symptoms and quality of life in pediatric patients, but few clinical practice studies have researched the effect of the therapy on severity- and disease-related biomarkers in this population, the study authors write.

The study was published online in Pediatric Allergy Immunology.

In a new study, a team led by Esmé Kamphuis, MD, of the University of Groningen, the Netherlands, and colleagues evaluated the efficacy and safety of a 28-week dupilumab treatment course in 61 pediatric patients with moderate to severe AD. Additionally, the investigators examined the effect of this treatment regimen on serum biomarkers associated with disease severity.

Patients in the study were registered in the multicenter BioDay registry, which includes patients with moderate to severe AD receiving biologics or small-molecule agents. The AD cohort included children between 6 and 12 years of age (n = 16) and adolescents between 12 and less than 18 years of age (n = 45), all of whom received dupilumab on a dosing regimen indicated by age and body weight.

Over one-third (36.1%) of dupilumab-treated patients achieved an Investigator Global Assessment score of “almost clear” by 28 weeks of treatment. Approximately 75.4% of patients reached an Eczema Area and Severity Index (EASI) of 50, 49.2% reached EASI-75, and 24.6% reached EASI-90 at the 7-month follow-up.

Among patient-reported outcomes, 84.7% experienced improvements of 4 or more points on the Patient-Oriented Eczema Measure after the 28-week dupilumab treatment. In addition, improvements of 4 or more points on the Numeric Rating Scale for pruritus and pain were achieved by 45.3% and 77.4% of patients, respectively.

The most frequently reported side effects included conjunctivitis (n = 10) and headache (n = 4).

Of the 19 severity-associated serum biomarkers measured at baseline, week 4, and week 16, markers related to AD severity and treatment response significantly decreased during treatment (thymus- and activation-regulated chemokine, pulmonary and activation-regulated chemokine, periostin, soluble IL-2 receptor alpha).

A predicted EASI, calculated from selected biomarkers, demonstrated a significant association with disease severity in the cohort.
 

Implications for practice

When asked to comment on the study findings, Raegan Hunt, MD, the division chief of pediatric dermatology at Texas Children’s Hospital in Houston, said it is important to validate the changes in AD serum biomarkers in pediatric patients on dupilumab therapy, given that this treatment has historically been better studied in adults.

“This study adds to daily practice outcomes data, which in many cases is more relevant to the everyday care of patients than structured clinical trial data,” said Dr. Hunt, an associate professor at the Baylor College of Medicine, Houston.

Dr. Hunt, who didn’t participate in the study, noted that more research is needed on the adverse effects of dupilumab in the pediatric AD population.

Dr. Hui added that there is a lack of clear understanding of the exact underlying mechanisms for certain side effects, such as conjunctivitis, warranting further study.

The study’s BioDay registry is funded by Sanofi/Regeneron, AbbVie, Leo Pharma, Pfizer, and Eli Lilly. Several study coauthors report relationships with several pharmaceutical companies. Dr. Hunt and Dr. Hui report no relevant financial relationships.

A version of this article first appeared on Medscape.com.

A registry-based study provides further evidence that treatment with dupilumab significantly reduces severity and symptoms of atopic dermatitis (AD) in clinical practice.

Dupilumab also decreased severity-associated biomarkers in pediatric patients with moderate to severe AD, researchers in the Netherlands reported.

Obtaining serum biomarkers is not the current standard in everyday practice, but studying them may improve understanding of who might respond best to dupilumab, said Jessica Hui, MD, a pediatric allergist and immunologist at National Jewish Health in Denver, in an email comment to this news organization.

“AD is heterogeneous, as each patient may have different presentations and underlying biology,” said Dr. Hui, who wasn’t involved in the research. “Studying biomarkers can eventually assist us in providing targeted therapy to each individual patient.”

Dr. Hui added, “As blood biomarkers can inform us of severity and treatment response, we can be hopeful that this will assist us in the management of AD patients in the future.”
 

Examining effect on disease severity

Dupilumab, a monoclonal antibody that inhibits interleukin (IL)-4 and IL-13 signaling, is approved in Europe and the United States to treat moderate to severe AD in patients 6 months of age or older, and to treat certain other inflammatory conditions.

Phase 3 studies show that dupilumab is effective for improving AD symptoms and quality of life in pediatric patients, but few clinical practice studies have researched the effect of the therapy on severity- and disease-related biomarkers in this population, the study authors write.

The study was published online in Pediatric Allergy Immunology.

In a new study, a team led by Esmé Kamphuis, MD, of the University of Groningen, the Netherlands, and colleagues evaluated the efficacy and safety of a 28-week dupilumab treatment course in 61 pediatric patients with moderate to severe AD. Additionally, the investigators examined the effect of this treatment regimen on serum biomarkers associated with disease severity.

Patients in the study were registered in the multicenter BioDay registry, which includes patients with moderate to severe AD receiving biologics or small-molecule agents. The AD cohort included children between 6 and 12 years of age (n = 16) and adolescents between 12 and less than 18 years of age (n = 45), all of whom received dupilumab on a dosing regimen indicated by age and body weight.

Over one-third (36.1%) of dupilumab-treated patients achieved an Investigator Global Assessment score of “almost clear” by 28 weeks of treatment. Approximately 75.4% of patients reached an Eczema Area and Severity Index (EASI) of 50, 49.2% reached EASI-75, and 24.6% reached EASI-90 at the 7-month follow-up.

Among patient-reported outcomes, 84.7% experienced improvements of 4 or more points on the Patient-Oriented Eczema Measure after the 28-week dupilumab treatment. In addition, improvements of 4 or more points on the Numeric Rating Scale for pruritus and pain were achieved by 45.3% and 77.4% of patients, respectively.

The most frequently reported side effects included conjunctivitis (n = 10) and headache (n = 4).

Of the 19 severity-associated serum biomarkers measured at baseline, week 4, and week 16, markers related to AD severity and treatment response significantly decreased during treatment (thymus- and activation-regulated chemokine, pulmonary and activation-regulated chemokine, periostin, soluble IL-2 receptor alpha).

A predicted EASI, calculated from selected biomarkers, demonstrated a significant association with disease severity in the cohort.
 

Implications for practice

When asked to comment on the study findings, Raegan Hunt, MD, the division chief of pediatric dermatology at Texas Children’s Hospital in Houston, said it is important to validate the changes in AD serum biomarkers in pediatric patients on dupilumab therapy, given that this treatment has historically been better studied in adults.

“This study adds to daily practice outcomes data, which in many cases is more relevant to the everyday care of patients than structured clinical trial data,” said Dr. Hunt, an associate professor at the Baylor College of Medicine, Houston.

Dr. Hunt, who didn’t participate in the study, noted that more research is needed on the adverse effects of dupilumab in the pediatric AD population.

Dr. Hui added that there is a lack of clear understanding of the exact underlying mechanisms for certain side effects, such as conjunctivitis, warranting further study.

The study’s BioDay registry is funded by Sanofi/Regeneron, AbbVie, Leo Pharma, Pfizer, and Eli Lilly. Several study coauthors report relationships with several pharmaceutical companies. Dr. Hunt and Dr. Hui report no relevant financial relationships.

A version of this article first appeared on Medscape.com.

The interleukin-12/23 inhibitor ustekinumab (Stelara) is nearly as effective as a tumor necrosis factor (TNF) inhibitor for psoriatic arthritis, and patients are slightly more likely to persist with it and have a lower rate of adverse events, a 3-year, real-world study has found.

In a paper published online in Annals of the Rheumatic Diseases, researchers presented the outcomes of the prospective, observational PsABio study of 895 adults with psoriatic arthritis, who were starting treatment for the first time with either ustekinumab or a TNF inhibitor as first-, second-, or third-line treatment.

At 3 years after starting therapy, 49.9% of the 439 patients prescribed ustekinumab were still on that treatment, compared with 47.8% of the 456 patients prescribed a TNF inhibitor. However, there were differences in persistence based on clinical presentation. Patients who had severe skin involvement who were treated with ustekinumab stayed on the drug for longer than did those with severe skin involvement treated with a TNF inhibitor, and they were more likely to persist with their treatment for the 3 years of the study. However, there were numerically more patients with mild or moderate skin involvement taking a TNF inhibitor who stayed persistent with the treatment, compared with those taking ustekinumab, although the differences were not statistically significant.

“In the ustekinumab group, skin response was an important reason for prolonged persistence, with more patients in the ustekinumab group stopping/switching due to lack of effectiveness,” wrote Laure Gossec, MD, of Pitié-Salpêtrière Hospital and Sorbonne University, Paris, and coauthors. “This is expected, as psoriasis can significantly affect morbidity, and successfully treating skin symptoms improves patients’ health-related quality of life.”

The authors also noted that patients on ustekinumab monotherapy had the highest rate of persistence and stayed on treatment longer than did those on TNF inhibitor monotherapy, or on dual therapy with either drug combined with methotrexate. They suggested this could be because patients on TNF inhibitor monotherapy may be more likely to develop antidrug antibodies than those on ustekinumab monotherapy. It could also be because adding methotrexate may increase the risk of adverse events, but without necessarily increasing the effectiveness of ustekinumab on skin involvement.

In terms of efficacy, researchers saw that 69.8% of patients in the TNF inhibitor group had achieved low disease activity and 45% had achieved remission, compared with 58.6% of patients in the ustekinumab group who achieved low disease activity and 31.4% who achieved remission.

A similar pattern was seen for minimal disease activity and very low disease activity, which were achieved by 54.2% and 26.9% respectively of those in the TNF inhibitor group, and 41.4% and 19.2% respectively of those in the ustekinumab group.

Because the study was observational and real-world, the choice of therapy was made by the treating rheumatologist rather than patients being randomized. There were some baseline differences between the ustekinumab and TNF inhibitor groups; for example, patients in ustekinumab group were generally older and with more comorbidities, and were more likely to have previous been treated with biologics. However, they were also less likely to be concurrently treated with methotrexate and NSAIDs, and more likely to have severe skin involvement.

The study saw a higher rate of adverse events in the TNF inhibitor group, compared with the ustekinumab, with 39.7% of patients treated with TNF inhibitor and 34.6% of those treated with ustekinumab reporting at least one adverse event. The rates of serious adverse events and malignancies were similar for the two groups, but overall the ustekinumab group had a lower rate of clinically-relevant adverse events including infections.

The study was sponsored by Janssen, which markets ustekinumab. Ten authors declared personal fees, grants, and nonfinancial support from the pharmaceutical sector, including Janssen. One author was an employee of Janssen, one an employee of Johnson & Johnson, and two are editorial board members of Annals of the Rheumatic Diseases.

The interleukin-12/23 inhibitor ustekinumab (Stelara) is nearly as effective as a tumor necrosis factor (TNF) inhibitor for psoriatic arthritis, and patients are slightly more likely to persist with it and have a lower rate of adverse events, a 3-year, real-world study has found.

In a paper published online in Annals of the Rheumatic Diseases, researchers presented the outcomes of the prospective, observational PsABio study of 895 adults with psoriatic arthritis, who were starting treatment for the first time with either ustekinumab or a TNF inhibitor as first-, second-, or third-line treatment.

At 3 years after starting therapy, 49.9% of the 439 patients prescribed ustekinumab were still on that treatment, compared with 47.8% of the 456 patients prescribed a TNF inhibitor. However, there were differences in persistence based on clinical presentation. Patients who had severe skin involvement who were treated with ustekinumab stayed on the drug for longer than did those with severe skin involvement treated with a TNF inhibitor, and they were more likely to persist with their treatment for the 3 years of the study. However, there were numerically more patients with mild or moderate skin involvement taking a TNF inhibitor who stayed persistent with the treatment, compared with those taking ustekinumab, although the differences were not statistically significant.

“In the ustekinumab group, skin response was an important reason for prolonged persistence, with more patients in the ustekinumab group stopping/switching due to lack of effectiveness,” wrote Laure Gossec, MD, of Pitié-Salpêtrière Hospital and Sorbonne University, Paris, and coauthors. “This is expected, as psoriasis can significantly affect morbidity, and successfully treating skin symptoms improves patients’ health-related quality of life.”

The authors also noted that patients on ustekinumab monotherapy had the highest rate of persistence and stayed on treatment longer than did those on TNF inhibitor monotherapy, or on dual therapy with either drug combined with methotrexate. They suggested this could be because patients on TNF inhibitor monotherapy may be more likely to develop antidrug antibodies than those on ustekinumab monotherapy. It could also be because adding methotrexate may increase the risk of adverse events, but without necessarily increasing the effectiveness of ustekinumab on skin involvement.

In terms of efficacy, researchers saw that 69.8% of patients in the TNF inhibitor group had achieved low disease activity and 45% had achieved remission, compared with 58.6% of patients in the ustekinumab group who achieved low disease activity and 31.4% who achieved remission.

A similar pattern was seen for minimal disease activity and very low disease activity, which were achieved by 54.2% and 26.9% respectively of those in the TNF inhibitor group, and 41.4% and 19.2% respectively of those in the ustekinumab group.

Because the study was observational and real-world, the choice of therapy was made by the treating rheumatologist rather than patients being randomized. There were some baseline differences between the ustekinumab and TNF inhibitor groups; for example, patients in ustekinumab group were generally older and with more comorbidities, and were more likely to have previous been treated with biologics. However, they were also less likely to be concurrently treated with methotrexate and NSAIDs, and more likely to have severe skin involvement.

The study saw a higher rate of adverse events in the TNF inhibitor group, compared with the ustekinumab, with 39.7% of patients treated with TNF inhibitor and 34.6% of those treated with ustekinumab reporting at least one adverse event. The rates of serious adverse events and malignancies were similar for the two groups, but overall the ustekinumab group had a lower rate of clinically-relevant adverse events including infections.

The study was sponsored by Janssen, which markets ustekinumab. Ten authors declared personal fees, grants, and nonfinancial support from the pharmaceutical sector, including Janssen. One author was an employee of Janssen, one an employee of Johnson & Johnson, and two are editorial board members of Annals of the Rheumatic Diseases.

The interleukin-12/23 inhibitor ustekinumab (Stelara) is nearly as effective as a tumor necrosis factor (TNF) inhibitor for psoriatic arthritis, and patients are slightly more likely to persist with it and have a lower rate of adverse events, a 3-year, real-world study has found.

In a paper published online in Annals of the Rheumatic Diseases, researchers presented the outcomes of the prospective, observational PsABio study of 895 adults with psoriatic arthritis, who were starting treatment for the first time with either ustekinumab or a TNF inhibitor as first-, second-, or third-line treatment.

At 3 years after starting therapy, 49.9% of the 439 patients prescribed ustekinumab were still on that treatment, compared with 47.8% of the 456 patients prescribed a TNF inhibitor. However, there were differences in persistence based on clinical presentation. Patients who had severe skin involvement who were treated with ustekinumab stayed on the drug for longer than did those with severe skin involvement treated with a TNF inhibitor, and they were more likely to persist with their treatment for the 3 years of the study. However, there were numerically more patients with mild or moderate skin involvement taking a TNF inhibitor who stayed persistent with the treatment, compared with those taking ustekinumab, although the differences were not statistically significant.

“In the ustekinumab group, skin response was an important reason for prolonged persistence, with more patients in the ustekinumab group stopping/switching due to lack of effectiveness,” wrote Laure Gossec, MD, of Pitié-Salpêtrière Hospital and Sorbonne University, Paris, and coauthors. “This is expected, as psoriasis can significantly affect morbidity, and successfully treating skin symptoms improves patients’ health-related quality of life.”

The authors also noted that patients on ustekinumab monotherapy had the highest rate of persistence and stayed on treatment longer than did those on TNF inhibitor monotherapy, or on dual therapy with either drug combined with methotrexate. They suggested this could be because patients on TNF inhibitor monotherapy may be more likely to develop antidrug antibodies than those on ustekinumab monotherapy. It could also be because adding methotrexate may increase the risk of adverse events, but without necessarily increasing the effectiveness of ustekinumab on skin involvement.

In terms of efficacy, researchers saw that 69.8% of patients in the TNF inhibitor group had achieved low disease activity and 45% had achieved remission, compared with 58.6% of patients in the ustekinumab group who achieved low disease activity and 31.4% who achieved remission.

A similar pattern was seen for minimal disease activity and very low disease activity, which were achieved by 54.2% and 26.9% respectively of those in the TNF inhibitor group, and 41.4% and 19.2% respectively of those in the ustekinumab group.

Because the study was observational and real-world, the choice of therapy was made by the treating rheumatologist rather than patients being randomized. There were some baseline differences between the ustekinumab and TNF inhibitor groups; for example, patients in ustekinumab group were generally older and with more comorbidities, and were more likely to have previous been treated with biologics. However, they were also less likely to be concurrently treated with methotrexate and NSAIDs, and more likely to have severe skin involvement.

The study saw a higher rate of adverse events in the TNF inhibitor group, compared with the ustekinumab, with 39.7% of patients treated with TNF inhibitor and 34.6% of those treated with ustekinumab reporting at least one adverse event. The rates of serious adverse events and malignancies were similar for the two groups, but overall the ustekinumab group had a lower rate of clinically-relevant adverse events including infections.

The study was sponsored by Janssen, which markets ustekinumab. Ten authors declared personal fees, grants, and nonfinancial support from the pharmaceutical sector, including Janssen. One author was an employee of Janssen, one an employee of Johnson & Johnson, and two are editorial board members of Annals of the Rheumatic Diseases.

A biopsy of the edge of one of lesions on the torso was performed. Histopathology demonstrated hyperkeratosis of the stratum corneum with focal thickening of the granular cell layer, basal layer degeneration of the epidermis, and a band-like subepidermal lymphocytic infiltrate with Civatte bodies consistent with lichen planus. There was some reduction in the elastic fibers on the papillary dermis.

Courtesy Dr. Zhe Piao

Given the morphology of the lesions and the histopathologic presentation, he was diagnosed with annular atrophic lichen planus (AALP). Lichen planus is a chronic inflammatory condition that can affect the skin, nails, hair, and mucosa. Lichen planus is seen in less than 1% of the population, occurring mainly in middle-aged adults and rarely seen in children. Though, there appears to be no clear racial predilection, a small study in the United States showed a higher incidence of lichen planus in Black children. Lesions with classic characteristics are pruritic, polygonal, violaceous, flat-topped papules and plaques.

There are different subtypes of lichen planus, which include papular or classic form, hypertrophic, vesiculobullous, actinic, annular, atrophic, annular atrophic, linear, follicular, lichen planus pigmentosus, lichen pigmentosa pigmentosus-inversus, lichen planus–lupus erythematosus overlap syndrome, and lichen planus pemphigoides. The annular atrophic form is the least common of all, and there are few reports in the pediatric population. AALP presents as annular papules and plaques with atrophic centers that resolve within a few months leaving postinflammatory hypo- or hyperpigmentation and, in some patients, permanent atrophic scarring.

In histopathology, the lesions show the classic characteristics of lichen planus including vacuolar interface changes and necrotic keratinocytes, hypergranulosis, band-like infiltrate in the dermis, melanin incontinence, and Civatte bodies. In AALP, the center of the lesion shows an atrophic epidermis, and there is also a characteristic partial reduction to complete destruction of elastic fibers in the papillary dermis in the center of the lesion and sometimes in the periphery as well, which helps differentiate AALP from other forms of lichen planus.

The differential diagnosis for AALP includes tinea corporis, which can present with annular lesions, but they are usually scaly and rarely resolve on their own. Pityriasis rosea lesions can also look very similar to AALP lesions, but the difference is the presence of an inner collaret of scale and a lack of atrophy in pityriasis rosea. Pityriasis rosea is a rash that can be triggered by viral infections, medications, and vaccines and self-resolves within 10-12 weeks. Secondary syphilis can also be annular and resemble lesions of AALP. Syphilis patients are usually sexually active and may have lesions present on the palms and soles, which were not seen in our patient.

Granuloma annulare should also be included in the differential diagnosis of AALP. Granuloma annulare lesions present as annular papules or plaques with raised borders and a slightly hyperpigmented center that may appear more depressed compared to the edges of the lesion, though not atrophic as seen in AALP. Pityriasis lichenoides chronica is an inflammatory condition of the skin in which patients present with erythematous to brown papules in different stages which may have a mica-like scale, usually not seen on AALP. Sometimes a skin biopsy will be needed to differentiate between these conditions.

It is very important to make a timely diagnosis of AALP and treat the lesions early as it may leave long-lasting dyspigmentation and scarring. Though AAPL lesions can be resistant to treatment with topical medications, there are reports of improvement with superpotent topical corticosteroids and calcineurin inhibitors. In recalcitrant cases, systemic therapy with isotretinoin, acitretin, methotrexate, systemic corticosteroids, dapsone, and hydroxychloroquine can be considered. Our patient was treated with clobetasol propionate ointment 0.05% with good response.

Dr. Matiz is a pediatric dermatologist at Southern California Permanente Medical Group, San Diego.
 

References

Bowers S and Warshaw EM. J Am Acad Dermatol. 2006 Oct;55(4):557-72; quiz 573-6.

Gorouhi F et al. Scientific World Journal. 2014 Jan 30;2014:742826.

Santhosh P and George M. Int J Dermatol. 2022.61:1213-7.

Sears S et al. Pediatr Dermatol. 2021;38:1283-7.

Weston G and Payette M. Int J Womens Dermatol. 2015 Sep 16;1(3):140-9.

A biopsy of the edge of one of lesions on the torso was performed. Histopathology demonstrated hyperkeratosis of the stratum corneum with focal thickening of the granular cell layer, basal layer degeneration of the epidermis, and a band-like subepidermal lymphocytic infiltrate with Civatte bodies consistent with lichen planus. There was some reduction in the elastic fibers on the papillary dermis.

Courtesy Dr. Zhe Piao

Given the morphology of the lesions and the histopathologic presentation, he was diagnosed with annular atrophic lichen planus (AALP). Lichen planus is a chronic inflammatory condition that can affect the skin, nails, hair, and mucosa. Lichen planus is seen in less than 1% of the population, occurring mainly in middle-aged adults and rarely seen in children. Though, there appears to be no clear racial predilection, a small study in the United States showed a higher incidence of lichen planus in Black children. Lesions with classic characteristics are pruritic, polygonal, violaceous, flat-topped papules and plaques.

There are different subtypes of lichen planus, which include papular or classic form, hypertrophic, vesiculobullous, actinic, annular, atrophic, annular atrophic, linear, follicular, lichen planus pigmentosus, lichen pigmentosa pigmentosus-inversus, lichen planus–lupus erythematosus overlap syndrome, and lichen planus pemphigoides. The annular atrophic form is the least common of all, and there are few reports in the pediatric population. AALP presents as annular papules and plaques with atrophic centers that resolve within a few months leaving postinflammatory hypo- or hyperpigmentation and, in some patients, permanent atrophic scarring.

In histopathology, the lesions show the classic characteristics of lichen planus including vacuolar interface changes and necrotic keratinocytes, hypergranulosis, band-like infiltrate in the dermis, melanin incontinence, and Civatte bodies. In AALP, the center of the lesion shows an atrophic epidermis, and there is also a characteristic partial reduction to complete destruction of elastic fibers in the papillary dermis in the center of the lesion and sometimes in the periphery as well, which helps differentiate AALP from other forms of lichen planus.

The differential diagnosis for AALP includes tinea corporis, which can present with annular lesions, but they are usually scaly and rarely resolve on their own. Pityriasis rosea lesions can also look very similar to AALP lesions, but the difference is the presence of an inner collaret of scale and a lack of atrophy in pityriasis rosea. Pityriasis rosea is a rash that can be triggered by viral infections, medications, and vaccines and self-resolves within 10-12 weeks. Secondary syphilis can also be annular and resemble lesions of AALP. Syphilis patients are usually sexually active and may have lesions present on the palms and soles, which were not seen in our patient.

Granuloma annulare should also be included in the differential diagnosis of AALP. Granuloma annulare lesions present as annular papules or plaques with raised borders and a slightly hyperpigmented center that may appear more depressed compared to the edges of the lesion, though not atrophic as seen in AALP. Pityriasis lichenoides chronica is an inflammatory condition of the skin in which patients present with erythematous to brown papules in different stages which may have a mica-like scale, usually not seen on AALP. Sometimes a skin biopsy will be needed to differentiate between these conditions.

It is very important to make a timely diagnosis of AALP and treat the lesions early as it may leave long-lasting dyspigmentation and scarring. Though AAPL lesions can be resistant to treatment with topical medications, there are reports of improvement with superpotent topical corticosteroids and calcineurin inhibitors. In recalcitrant cases, systemic therapy with isotretinoin, acitretin, methotrexate, systemic corticosteroids, dapsone, and hydroxychloroquine can be considered. Our patient was treated with clobetasol propionate ointment 0.05% with good response.

Dr. Matiz is a pediatric dermatologist at Southern California Permanente Medical Group, San Diego.
 

References

Bowers S and Warshaw EM. J Am Acad Dermatol. 2006 Oct;55(4):557-72; quiz 573-6.

Gorouhi F et al. Scientific World Journal. 2014 Jan 30;2014:742826.

Santhosh P and George M. Int J Dermatol. 2022.61:1213-7.

Sears S et al. Pediatr Dermatol. 2021;38:1283-7.

Weston G and Payette M. Int J Womens Dermatol. 2015 Sep 16;1(3):140-9.

A biopsy of the edge of one of lesions on the torso was performed. Histopathology demonstrated hyperkeratosis of the stratum corneum with focal thickening of the granular cell layer, basal layer degeneration of the epidermis, and a band-like subepidermal lymphocytic infiltrate with Civatte bodies consistent with lichen planus. There was some reduction in the elastic fibers on the papillary dermis.

Courtesy Dr. Zhe Piao

Given the morphology of the lesions and the histopathologic presentation, he was diagnosed with annular atrophic lichen planus (AALP). Lichen planus is a chronic inflammatory condition that can affect the skin, nails, hair, and mucosa. Lichen planus is seen in less than 1% of the population, occurring mainly in middle-aged adults and rarely seen in children. Though, there appears to be no clear racial predilection, a small study in the United States showed a higher incidence of lichen planus in Black children. Lesions with classic characteristics are pruritic, polygonal, violaceous, flat-topped papules and plaques.

There are different subtypes of lichen planus, which include papular or classic form, hypertrophic, vesiculobullous, actinic, annular, atrophic, annular atrophic, linear, follicular, lichen planus pigmentosus, lichen pigmentosa pigmentosus-inversus, lichen planus–lupus erythematosus overlap syndrome, and lichen planus pemphigoides. The annular atrophic form is the least common of all, and there are few reports in the pediatric population. AALP presents as annular papules and plaques with atrophic centers that resolve within a few months leaving postinflammatory hypo- or hyperpigmentation and, in some patients, permanent atrophic scarring.

In histopathology, the lesions show the classic characteristics of lichen planus including vacuolar interface changes and necrotic keratinocytes, hypergranulosis, band-like infiltrate in the dermis, melanin incontinence, and Civatte bodies. In AALP, the center of the lesion shows an atrophic epidermis, and there is also a characteristic partial reduction to complete destruction of elastic fibers in the papillary dermis in the center of the lesion and sometimes in the periphery as well, which helps differentiate AALP from other forms of lichen planus.

The differential diagnosis for AALP includes tinea corporis, which can present with annular lesions, but they are usually scaly and rarely resolve on their own. Pityriasis rosea lesions can also look very similar to AALP lesions, but the difference is the presence of an inner collaret of scale and a lack of atrophy in pityriasis rosea. Pityriasis rosea is a rash that can be triggered by viral infections, medications, and vaccines and self-resolves within 10-12 weeks. Secondary syphilis can also be annular and resemble lesions of AALP. Syphilis patients are usually sexually active and may have lesions present on the palms and soles, which were not seen in our patient.

Granuloma annulare should also be included in the differential diagnosis of AALP. Granuloma annulare lesions present as annular papules or plaques with raised borders and a slightly hyperpigmented center that may appear more depressed compared to the edges of the lesion, though not atrophic as seen in AALP. Pityriasis lichenoides chronica is an inflammatory condition of the skin in which patients present with erythematous to brown papules in different stages which may have a mica-like scale, usually not seen on AALP. Sometimes a skin biopsy will be needed to differentiate between these conditions.

It is very important to make a timely diagnosis of AALP and treat the lesions early as it may leave long-lasting dyspigmentation and scarring. Though AAPL lesions can be resistant to treatment with topical medications, there are reports of improvement with superpotent topical corticosteroids and calcineurin inhibitors. In recalcitrant cases, systemic therapy with isotretinoin, acitretin, methotrexate, systemic corticosteroids, dapsone, and hydroxychloroquine can be considered. Our patient was treated with clobetasol propionate ointment 0.05% with good response.

Dr. Matiz is a pediatric dermatologist at Southern California Permanente Medical Group, San Diego.
 

References

Bowers S and Warshaw EM. J Am Acad Dermatol. 2006 Oct;55(4):557-72; quiz 573-6.

Gorouhi F et al. Scientific World Journal. 2014 Jan 30;2014:742826.

Santhosh P and George M. Int J Dermatol. 2022.61:1213-7.

Sears S et al. Pediatr Dermatol. 2021;38:1283-7.

Weston G and Payette M. Int J Womens Dermatol. 2015 Sep 16;1(3):140-9.

These hyperpigmented lesions with fine scale on the outer edges are characteristic of pityriasis versicolor, also known as tinea versicolor. These macules (or patches) are commonly found on the trunk, proximal extremities, or neck. The lesions can be hypopigmented (pityriasis versicolor alba), hyperpigmented (pityriasis versicolor nigra), or erythematous (pityriasis versicolor rubra).¹ It is common to see hyperpigmentation in people with darker skin tones, as was the case with this patient. Pityriasis versicolor is often asymptomatic, but patients may describe mild to moderate pruritis.

Pityriasis versicolor is a common fungal infection of the superficial layers of the dermis caused by Malassezia furfur.² Impaired immunity and excessive sweating are risk factors for pityriasis versicolor; other risk factors include having a family member with tinea versicolor and living in a hot, humid region.¹ Adolescents and young adults are most often affected.¹

An evoked scale sign is a helpful tool to confirm the diagnosis clinically.³ Scale will appear when you stretch the affected skin with your thumb and index finger (or you scrape the area with a scalpel blade).³ If there is doubt about the diagnosis, use a potassium hydroxide (KOH) preparation; a positive test will reveal the classic “spaghetti and meatballs” pattern.¹

Selenium sulfide 2.5%, zinc pyrithione 1%, and ketoconazole 2% shampoo are effective topical treatments. The shampoo is applied full strength to the affected skin daily for 5 to 10 minutes before it’s washed off. This can be done for 1 to 4 weeks, with longer treatment courses resulting in higher cure rates. Systemic therapy is reserved for patients with widespread infection or those who do not respond to topical treatment.⁴ It’s important to advise patients that the restoration of normal skin pigmentation can takes months.

This patient was treated with ketoconazole 2% shampoo for 3 weeks. A complete return of skin color was achieved 6 months after completion of therapy.

‌

Image courtesy of Judy Jasser, MD. Text courtesy of Judy Jasser, MD, Department of Pediatrics, and Daniel Stulberg, MD, FAAFP, Professor and Chair, Department of Family and Community Medicine, Western Michigan University Homer Stryker, MD School of Medicine, Kalamazoo.

These hyperpigmented lesions with fine scale on the outer edges are characteristic of pityriasis versicolor, also known as tinea versicolor. These macules (or patches) are commonly found on the trunk, proximal extremities, or neck. The lesions can be hypopigmented (pityriasis versicolor alba), hyperpigmented (pityriasis versicolor nigra), or erythematous (pityriasis versicolor rubra).¹ It is common to see hyperpigmentation in people with darker skin tones, as was the case with this patient. Pityriasis versicolor is often asymptomatic, but patients may describe mild to moderate pruritis.

Pityriasis versicolor is a common fungal infection of the superficial layers of the dermis caused by Malassezia furfur.² Impaired immunity and excessive sweating are risk factors for pityriasis versicolor; other risk factors include having a family member with tinea versicolor and living in a hot, humid region.¹ Adolescents and young adults are most often affected.¹

An evoked scale sign is a helpful tool to confirm the diagnosis clinically.³ Scale will appear when you stretch the affected skin with your thumb and index finger (or you scrape the area with a scalpel blade).³ If there is doubt about the diagnosis, use a potassium hydroxide (KOH) preparation; a positive test will reveal the classic “spaghetti and meatballs” pattern.¹

Selenium sulfide 2.5%, zinc pyrithione 1%, and ketoconazole 2% shampoo are effective topical treatments. The shampoo is applied full strength to the affected skin daily for 5 to 10 minutes before it’s washed off. This can be done for 1 to 4 weeks, with longer treatment courses resulting in higher cure rates. Systemic therapy is reserved for patients with widespread infection or those who do not respond to topical treatment.⁴ It’s important to advise patients that the restoration of normal skin pigmentation can takes months.

This patient was treated with ketoconazole 2% shampoo for 3 weeks. A complete return of skin color was achieved 6 months after completion of therapy.

‌

Image courtesy of Judy Jasser, MD. Text courtesy of Judy Jasser, MD, Department of Pediatrics, and Daniel Stulberg, MD, FAAFP, Professor and Chair, Department of Family and Community Medicine, Western Michigan University Homer Stryker, MD School of Medicine, Kalamazoo.

These hyperpigmented lesions with fine scale on the outer edges are characteristic of pityriasis versicolor, also known as tinea versicolor. These macules (or patches) are commonly found on the trunk, proximal extremities, or neck. The lesions can be hypopigmented (pityriasis versicolor alba), hyperpigmented (pityriasis versicolor nigra), or erythematous (pityriasis versicolor rubra).¹ It is common to see hyperpigmentation in people with darker skin tones, as was the case with this patient. Pityriasis versicolor is often asymptomatic, but patients may describe mild to moderate pruritis.

Pityriasis versicolor is a common fungal infection of the superficial layers of the dermis caused by Malassezia furfur.² Impaired immunity and excessive sweating are risk factors for pityriasis versicolor; other risk factors include having a family member with tinea versicolor and living in a hot, humid region.¹ Adolescents and young adults are most often affected.¹

An evoked scale sign is a helpful tool to confirm the diagnosis clinically.³ Scale will appear when you stretch the affected skin with your thumb and index finger (or you scrape the area with a scalpel blade).³ If there is doubt about the diagnosis, use a potassium hydroxide (KOH) preparation; a positive test will reveal the classic “spaghetti and meatballs” pattern.¹

Selenium sulfide 2.5%, zinc pyrithione 1%, and ketoconazole 2% shampoo are effective topical treatments. The shampoo is applied full strength to the affected skin daily for 5 to 10 minutes before it’s washed off. This can be done for 1 to 4 weeks, with longer treatment courses resulting in higher cure rates. Systemic therapy is reserved for patients with widespread infection or those who do not respond to topical treatment.⁴ It’s important to advise patients that the restoration of normal skin pigmentation can takes months.

This patient was treated with ketoconazole 2% shampoo for 3 weeks. A complete return of skin color was achieved 6 months after completion of therapy.

‌

Image courtesy of Judy Jasser, MD. Text courtesy of Judy Jasser, MD, Department of Pediatrics, and Daniel Stulberg, MD, FAAFP, Professor and Chair, Department of Family and Community Medicine, Western Michigan University Homer Stryker, MD School of Medicine, Kalamazoo.

THE COMPARISON

A and B Axilla of a 65-year-old White man with erythrasma showing a well-demarcated erythematous plaque with fine scale (A). Wood-lamp examination of the area showed characteristic bright coral red fluorescence (B).

C and D A well-demarcated, red-brown plaque with fine scale in the antecubital fossa of an obese Hispanic woman (C). Wood-lamp examination revealed bright coral red fluorescence (D).

E Hypopigmented patches (with pruritus) in the groin of a Black man. He also had erythrasma between the toes.

Erythrasma is a skin condition caused by acute or chronic infection of the outermost layer of the epidermis (stratum corneum) with Corynebacterium minutissimum. It has a predilection for intertriginous regions such as the axillae, groin, and interdigital spaces of the toes. It can be associated with pruritus or can be asymptomatic.

Epidemiology

Erythrasma typically affects adults, with greater prevalence among those residing in shared living facilities, such as dormitories or nursing homes, or in humid climates.¹ It is a common disorder with an estimated prevalence of 17.6% of bacterial skin infections in elderly patients and 44% of diabetic interdigital toe space infections.^2,3

Key clinical features

Erythrasma can manifest as red-brown hyperpigmented plaques with fine scale and little central clearing (FIGURES A and C) or as a hypopigmented patch (FIGURE E) with a sharply marginated, hyperpigmented border in patients with skin of color. In the interdigital toe spaces, the skin often is white and macerated. These findings may appear in patients of all skin tones.

Worth noting

• C minutissimum produces coproporphyrin III, which glows fluorescent red under Wood-lamp examination (FIGURES B and D). A recent shower or bath may remove the fluorescent coproporphyrins and cause a false-negative result. The interdigital space between the fourth and fifth toes is a common location for C minutissimum; thus clinicians should consider examining these areas with a Wood lamp.
• Associated risk factors include obesity, immunosuppression, diabetes mellitus, and excessive sweating.¹
• The differential diagnosis includes intertrigo, inverse psoriasis, confluent and reticulated papillomatosis (Gougerot-Carteaud syndrome), acanthosis nigricans, seborrheic dermatitis, and tinea pedis when present in the interdigital toe spaces. Plaques occurring in circular patterns may be mistaken for tinea corporis or pityriasis rotunda.
• There is a high prevalence of erythrasma in patients with inverse psoriasis, and it may exacerbate psoriatic plaques.⁴
• Treatment options include application of topical clindamycin or erythromycin to the affected area.1 Some patients have responded to topical mupiricin.2 For larger areas, a 1-g dose of clarithromycin⁵ or a 14-day course of erythromycin may be appropriate.¹ Avoid prescribing clarithromycin to patients with preexisting heart disease due to its increased risk for cardiac events or death; consider other agents.

Health disparity highlight

Obesity, most prevalent in non-Hispanic Black adults (49.9%) and Hispanic adults (45.6%) followed by non-Hispanic White adults (41.4%),⁶ may cause velvety dark plaques on the neck called acanthosis nigricans. However, acute or chronic erythrasma also may cause hyperpigmentation of the body folds. Although the pathology of erythrasma is due to bacterial infection of the superficial layer of the stratum corneum, acanthosis nigricans is due to fibroblast proliferation and stimulation of epidermal keratinocytes, likely from increased growth factors and insulinlike growth factor.⁷ If erythrasma is mistaken for acanthosis nigricans, the patient may be counseled inappropriately that the hyperpigmentation is something not easily resolved and subsequently left with an active treatable condition that adversely affects their quality of life.

THE COMPARISON

A and B Axilla of a 65-year-old White man with erythrasma showing a well-demarcated erythematous plaque with fine scale (A). Wood-lamp examination of the area showed characteristic bright coral red fluorescence (B).

C and D A well-demarcated, red-brown plaque with fine scale in the antecubital fossa of an obese Hispanic woman (C). Wood-lamp examination revealed bright coral red fluorescence (D).

E Hypopigmented patches (with pruritus) in the groin of a Black man. He also had erythrasma between the toes.

Erythrasma is a skin condition caused by acute or chronic infection of the outermost layer of the epidermis (stratum corneum) with Corynebacterium minutissimum. It has a predilection for intertriginous regions such as the axillae, groin, and interdigital spaces of the toes. It can be associated with pruritus or can be asymptomatic.

Epidemiology

Erythrasma typically affects adults, with greater prevalence among those residing in shared living facilities, such as dormitories or nursing homes, or in humid climates.¹ It is a common disorder with an estimated prevalence of 17.6% of bacterial skin infections in elderly patients and 44% of diabetic interdigital toe space infections.^2,3

Key clinical features

Erythrasma can manifest as red-brown hyperpigmented plaques with fine scale and little central clearing (FIGURES A and C) or as a hypopigmented patch (FIGURE E) with a sharply marginated, hyperpigmented border in patients with skin of color. In the interdigital toe spaces, the skin often is white and macerated. These findings may appear in patients of all skin tones.

Worth noting

• C minutissimum produces coproporphyrin III, which glows fluorescent red under Wood-lamp examination (FIGURES B and D). A recent shower or bath may remove the fluorescent coproporphyrins and cause a false-negative result. The interdigital space between the fourth and fifth toes is a common location for C minutissimum; thus clinicians should consider examining these areas with a Wood lamp.
• Associated risk factors include obesity, immunosuppression, diabetes mellitus, and excessive sweating.¹
• The differential diagnosis includes intertrigo, inverse psoriasis, confluent and reticulated papillomatosis (Gougerot-Carteaud syndrome), acanthosis nigricans, seborrheic dermatitis, and tinea pedis when present in the interdigital toe spaces. Plaques occurring in circular patterns may be mistaken for tinea corporis or pityriasis rotunda.
• There is a high prevalence of erythrasma in patients with inverse psoriasis, and it may exacerbate psoriatic plaques.⁴
• Treatment options include application of topical clindamycin or erythromycin to the affected area.1 Some patients have responded to topical mupiricin.2 For larger areas, a 1-g dose of clarithromycin⁵ or a 14-day course of erythromycin may be appropriate.¹ Avoid prescribing clarithromycin to patients with preexisting heart disease due to its increased risk for cardiac events or death; consider other agents.

Health disparity highlight

Obesity, most prevalent in non-Hispanic Black adults (49.9%) and Hispanic adults (45.6%) followed by non-Hispanic White adults (41.4%),⁶ may cause velvety dark plaques on the neck called acanthosis nigricans. However, acute or chronic erythrasma also may cause hyperpigmentation of the body folds. Although the pathology of erythrasma is due to bacterial infection of the superficial layer of the stratum corneum, acanthosis nigricans is due to fibroblast proliferation and stimulation of epidermal keratinocytes, likely from increased growth factors and insulinlike growth factor.⁷ If erythrasma is mistaken for acanthosis nigricans, the patient may be counseled inappropriately that the hyperpigmentation is something not easily resolved and subsequently left with an active treatable condition that adversely affects their quality of life.

THE COMPARISON

A and B Axilla of a 65-year-old White man with erythrasma showing a well-demarcated erythematous plaque with fine scale (A). Wood-lamp examination of the area showed characteristic bright coral red fluorescence (B).

C and D A well-demarcated, red-brown plaque with fine scale in the antecubital fossa of an obese Hispanic woman (C). Wood-lamp examination revealed bright coral red fluorescence (D).

E Hypopigmented patches (with pruritus) in the groin of a Black man. He also had erythrasma between the toes.

Erythrasma is a skin condition caused by acute or chronic infection of the outermost layer of the epidermis (stratum corneum) with Corynebacterium minutissimum. It has a predilection for intertriginous regions such as the axillae, groin, and interdigital spaces of the toes. It can be associated with pruritus or can be asymptomatic.

Epidemiology

Erythrasma typically affects adults, with greater prevalence among those residing in shared living facilities, such as dormitories or nursing homes, or in humid climates.¹ It is a common disorder with an estimated prevalence of 17.6% of bacterial skin infections in elderly patients and 44% of diabetic interdigital toe space infections.^2,3

Key clinical features

Erythrasma can manifest as red-brown hyperpigmented plaques with fine scale and little central clearing (FIGURES A and C) or as a hypopigmented patch (FIGURE E) with a sharply marginated, hyperpigmented border in patients with skin of color. In the interdigital toe spaces, the skin often is white and macerated. These findings may appear in patients of all skin tones.

Worth noting

• C minutissimum produces coproporphyrin III, which glows fluorescent red under Wood-lamp examination (FIGURES B and D). A recent shower or bath may remove the fluorescent coproporphyrins and cause a false-negative result. The interdigital space between the fourth and fifth toes is a common location for C minutissimum; thus clinicians should consider examining these areas with a Wood lamp.
• Associated risk factors include obesity, immunosuppression, diabetes mellitus, and excessive sweating.¹
• The differential diagnosis includes intertrigo, inverse psoriasis, confluent and reticulated papillomatosis (Gougerot-Carteaud syndrome), acanthosis nigricans, seborrheic dermatitis, and tinea pedis when present in the interdigital toe spaces. Plaques occurring in circular patterns may be mistaken for tinea corporis or pityriasis rotunda.
• There is a high prevalence of erythrasma in patients with inverse psoriasis, and it may exacerbate psoriatic plaques.⁴
• Treatment options include application of topical clindamycin or erythromycin to the affected area.1 Some patients have responded to topical mupiricin.2 For larger areas, a 1-g dose of clarithromycin⁵ or a 14-day course of erythromycin may be appropriate.¹ Avoid prescribing clarithromycin to patients with preexisting heart disease due to its increased risk for cardiac events or death; consider other agents.

Health disparity highlight

Obesity, most prevalent in non-Hispanic Black adults (49.9%) and Hispanic adults (45.6%) followed by non-Hispanic White adults (41.4%),⁶ may cause velvety dark plaques on the neck called acanthosis nigricans. However, acute or chronic erythrasma also may cause hyperpigmentation of the body folds. Although the pathology of erythrasma is due to bacterial infection of the superficial layer of the stratum corneum, acanthosis nigricans is due to fibroblast proliferation and stimulation of epidermal keratinocytes, likely from increased growth factors and insulinlike growth factor.⁷ If erythrasma is mistaken for acanthosis nigricans, the patient may be counseled inappropriately that the hyperpigmentation is something not easily resolved and subsequently left with an active treatable condition that adversely affects their quality of life.

A new generation of treatments appears to have caused U.S. melanoma mortality rates to plunge between 2013 and 2017 for the first time in 4 decades, a new study finds, although the dip appeared to stabilize over the next 2 years.

“This data is very encouraging and represents the real-world effectiveness of these newer therapies, which include immunotherapies and targeted therapies,” hematologist/oncologist Navkirat Kahlon, MD, MPH, of Seacoast Cancer Center and Massachusetts General Brigham Wentworth-Douglass Hospital, Dover, N.H., one of the study authors, said in an interview. In clinical trials, these new treatments “have been very effective ... so the timing as well as magnitude of drop seen in melanoma-specific population mortality was not at all surprising. But it’s still very exciting.”

The report, published in JAMA Network Open, tracked mortality rates for the deadliest form of skin cancer from 1975 to 2019. The researchers launched the study to better understand outcomes in cutaneous melanoma following the rise of new therapies that now provide options in addition to chemotherapy. “With the use of novel therapies, the survival of these patients has increased from a few weeks or months to many years in clinical trials,” Dr. Kahlon said. “Given the magnitude of benefit compared to traditional chemotherapy in clinical trials, we decided to see if the real-world U.S. population is deriving the same benefit.”

New drugs introduced in recent years include immunotherapy agents such as ipilimumab and targeted therapies such as vemurafenib.

The researchers analyzed age-adjusted melanoma outcome data from the Surveillance, Epidemiology, and End Results (SEER) database. In 1975, the long-term melanoma mortality rate for melanoma was 2.07 per 100,000 people (95% confidence interval [CI], 2.00-2.13). It rose to 2.65 (95% CI, 2.58-2.65) in 1988 and 2.67 (95% CI, 2.61-2.72) in 2013, then fell to 2.09 (95% CI, 2.05-2.14) in 2017 and 2.01 (95% CI, 1.97-2.06) in 2019.

Per the analysis, the rate grew at an annual percentage change (APC) of 1.65% (95% CI, 1.30%-2.00%, P < .001) from 1975 to 1988 and remained stable from 1988 to 2013 (P = .85). Then it fell by an APC of 6.28% (95% CI, –8.52% to –3.97%, P < .001) from 2013 to 2017. There was no statistically significant difference between 2017 and 2019, although “the trend was downward,” the authors noted.

“Our study didn’t study the parameters that can answer the question about how many more years of life patients are getting or how many lives aren’t lost,” Dr. Kahlon said in the interview. “But looking at other studies and clinical trial data, the prognosis of these patients with a historical median overall survival of a few weeks to months has improved to many months to years.”

But why do melanoma mortality rates remain roughly about the same as they were in 1975? “The incidence of melanoma has continued to rise,” she said. “Also, over time, we have become better at collecting more accurate information, so the [rate] in 1975 could potentially be an underestimated rate.”

In an interview, dermatologist Adewole “Ade” Adamson, MD, MPP, of the University of Texas at Austin, noted that a 2020 study examined melanoma death rates in Whites – who are most affected by melanoma – and found similar trends from 2013 to 2016. “Nothing about these [new] findings surprises me as they have been shown before. However, these confirmatory findings are reassuring because they show the powerful effect of novel treatments at a population level.”

A new generation of treatments appears to have caused U.S. melanoma mortality rates to plunge between 2013 and 2017 for the first time in 4 decades, a new study finds, although the dip appeared to stabilize over the next 2 years.

“This data is very encouraging and represents the real-world effectiveness of these newer therapies, which include immunotherapies and targeted therapies,” hematologist/oncologist Navkirat Kahlon, MD, MPH, of Seacoast Cancer Center and Massachusetts General Brigham Wentworth-Douglass Hospital, Dover, N.H., one of the study authors, said in an interview. In clinical trials, these new treatments “have been very effective ... so the timing as well as magnitude of drop seen in melanoma-specific population mortality was not at all surprising. But it’s still very exciting.”

The report, published in JAMA Network Open, tracked mortality rates for the deadliest form of skin cancer from 1975 to 2019. The researchers launched the study to better understand outcomes in cutaneous melanoma following the rise of new therapies that now provide options in addition to chemotherapy. “With the use of novel therapies, the survival of these patients has increased from a few weeks or months to many years in clinical trials,” Dr. Kahlon said. “Given the magnitude of benefit compared to traditional chemotherapy in clinical trials, we decided to see if the real-world U.S. population is deriving the same benefit.”

New drugs introduced in recent years include immunotherapy agents such as ipilimumab and targeted therapies such as vemurafenib.

The researchers analyzed age-adjusted melanoma outcome data from the Surveillance, Epidemiology, and End Results (SEER) database. In 1975, the long-term melanoma mortality rate for melanoma was 2.07 per 100,000 people (95% confidence interval [CI], 2.00-2.13). It rose to 2.65 (95% CI, 2.58-2.65) in 1988 and 2.67 (95% CI, 2.61-2.72) in 2013, then fell to 2.09 (95% CI, 2.05-2.14) in 2017 and 2.01 (95% CI, 1.97-2.06) in 2019.

Per the analysis, the rate grew at an annual percentage change (APC) of 1.65% (95% CI, 1.30%-2.00%, P < .001) from 1975 to 1988 and remained stable from 1988 to 2013 (P = .85). Then it fell by an APC of 6.28% (95% CI, –8.52% to –3.97%, P < .001) from 2013 to 2017. There was no statistically significant difference between 2017 and 2019, although “the trend was downward,” the authors noted.

“Our study didn’t study the parameters that can answer the question about how many more years of life patients are getting or how many lives aren’t lost,” Dr. Kahlon said in the interview. “But looking at other studies and clinical trial data, the prognosis of these patients with a historical median overall survival of a few weeks to months has improved to many months to years.”

But why do melanoma mortality rates remain roughly about the same as they were in 1975? “The incidence of melanoma has continued to rise,” she said. “Also, over time, we have become better at collecting more accurate information, so the [rate] in 1975 could potentially be an underestimated rate.”

In an interview, dermatologist Adewole “Ade” Adamson, MD, MPP, of the University of Texas at Austin, noted that a 2020 study examined melanoma death rates in Whites – who are most affected by melanoma – and found similar trends from 2013 to 2016. “Nothing about these [new] findings surprises me as they have been shown before. However, these confirmatory findings are reassuring because they show the powerful effect of novel treatments at a population level.”

A new generation of treatments appears to have caused U.S. melanoma mortality rates to plunge between 2013 and 2017 for the first time in 4 decades, a new study finds, although the dip appeared to stabilize over the next 2 years.

“This data is very encouraging and represents the real-world effectiveness of these newer therapies, which include immunotherapies and targeted therapies,” hematologist/oncologist Navkirat Kahlon, MD, MPH, of Seacoast Cancer Center and Massachusetts General Brigham Wentworth-Douglass Hospital, Dover, N.H., one of the study authors, said in an interview. In clinical trials, these new treatments “have been very effective ... so the timing as well as magnitude of drop seen in melanoma-specific population mortality was not at all surprising. But it’s still very exciting.”

The report, published in JAMA Network Open, tracked mortality rates for the deadliest form of skin cancer from 1975 to 2019. The researchers launched the study to better understand outcomes in cutaneous melanoma following the rise of new therapies that now provide options in addition to chemotherapy. “With the use of novel therapies, the survival of these patients has increased from a few weeks or months to many years in clinical trials,” Dr. Kahlon said. “Given the magnitude of benefit compared to traditional chemotherapy in clinical trials, we decided to see if the real-world U.S. population is deriving the same benefit.”

New drugs introduced in recent years include immunotherapy agents such as ipilimumab and targeted therapies such as vemurafenib.

The researchers analyzed age-adjusted melanoma outcome data from the Surveillance, Epidemiology, and End Results (SEER) database. In 1975, the long-term melanoma mortality rate for melanoma was 2.07 per 100,000 people (95% confidence interval [CI], 2.00-2.13). It rose to 2.65 (95% CI, 2.58-2.65) in 1988 and 2.67 (95% CI, 2.61-2.72) in 2013, then fell to 2.09 (95% CI, 2.05-2.14) in 2017 and 2.01 (95% CI, 1.97-2.06) in 2019.

Per the analysis, the rate grew at an annual percentage change (APC) of 1.65% (95% CI, 1.30%-2.00%, P < .001) from 1975 to 1988 and remained stable from 1988 to 2013 (P = .85). Then it fell by an APC of 6.28% (95% CI, –8.52% to –3.97%, P < .001) from 2013 to 2017. There was no statistically significant difference between 2017 and 2019, although “the trend was downward,” the authors noted.

“Our study didn’t study the parameters that can answer the question about how many more years of life patients are getting or how many lives aren’t lost,” Dr. Kahlon said in the interview. “But looking at other studies and clinical trial data, the prognosis of these patients with a historical median overall survival of a few weeks to months has improved to many months to years.”

But why do melanoma mortality rates remain roughly about the same as they were in 1975? “The incidence of melanoma has continued to rise,” she said. “Also, over time, we have become better at collecting more accurate information, so the [rate] in 1975 could potentially be an underestimated rate.”

In an interview, dermatologist Adewole “Ade” Adamson, MD, MPP, of the University of Texas at Austin, noted that a 2020 study examined melanoma death rates in Whites – who are most affected by melanoma – and found similar trends from 2013 to 2016. “Nothing about these [new] findings surprises me as they have been shown before. However, these confirmatory findings are reassuring because they show the powerful effect of novel treatments at a population level.”

Hidradenitis suppurativa (HS), also known as acne inversa or Verneuil disease, is a chronic, recurrent, inflammatory occlusive disease affecting the terminal follicular epithelium in apocrine gland–bearing skin areas.¹ HS manifests as painful nodules, abscesses, fistulas, and scarring and often has a severe psychological impact on the affected patient.²

When HS was first identified in the 1800s, it was believed to result from a dysfunction of the sweat glands.³ In 1939, scientists identified the true cause: follicular occlusion.³

Due to its chronic nature, heterogeneity in presentation, and apparent low prevalence,⁴ HS is considered an orphan disease.⁵ Over the past 10 years, there has been a surge in HS research—particularly in medical management—which has provided a better understanding of this condition.^6,7

In this review, we discuss the most updated evidence regarding the diagnosis and treatment of HS to guide the family physician (FP)’s approach to managing this debilitating disease. But first, we offer a word about the etiology and pathophysiology of the condition.

3 events set the stage for hidradenitis suppurativa

Although the exact cause of HS is still unknown, some researchers have hypothesized that HS results from a combination of genetic predisposition and environmental and lifestyle factors.^8-12 The primary mechanism of HS is the obstruction of the terminal follicular epithelium by a keratin plug.^1,13,14 A systematic review of molecular inflammatory pathways involved in HS divides the pathogenesis of HS into 3 events: follicular occlusion followed by dilation, follicular rupture and inflammatory response, and chronic inflammatory state with sinus tracts.⁸

An underreported condition

HS is often underreported and misdiagnosed.^4,15 Globally, the prevalence of HS varies from < 1% to 4%.^15,16 A systematic review with meta-analysis showed a higher prevalence of HS in females compared to males in American and European populations.¹⁷ In the United States, the overall frequency of HS is 0.1%, or 98 per 100,000 persons.¹⁶ The prevalence of HS is highest among patients ages 30 to 39 years; there is decreased prevalence in patients ages 55 years and older.^16,18

Who is at heightened risk?

Recent research has shown a relationship between ethnicity and HS.^16,19,20 African American and biracial groups (defined as African American and White) have a 3-fold and 2-fold greater prevalence of HS, respectively, compared to White patients.¹⁶ However, the prevalence of HS in non-White ethnic groups may be underestimated in clinical trials due to a lack of representation and subgroup analyses based on ethnicity, which may affect generalizability in HS recommendations.²¹

Continue to: Genetic predisposition

Genetic predisposition. As many as 40% of patients with HS report having at least 1 affected family member. A positive family history of HS is associated with earlier onset, longer disease duration, and severe disease.²² HS is genetically heterogeneous, and several mutations (eg, gamma secretase, PSTPIP1, PSEN1 genes) have been identified in patients and in vitro as the cause of dysregulation of epidermal proliferation and differentiation, immune dysregulation, and promotion of amyloid formation.^8,23-25

Obesity and metabolic risk factors. There is a strong relationship between HS and obesity. As many as 70% of patients with HS are obese, and 9% to 40% have metabolic syndrome.^12,18,26-28 Obesity is associated with maceration and mechanical stress, increased fragility of the dermo-epidermal junction, changes in cutaneous blood flow, and subdermal fat inflammation—all of which favor the pathophysiology of HS.^29,30

Smoking. Tobacco smoking is associated with severe HS and a lower chance of remission.¹² Population-based studies have shown that as many as 90% of patients with HS have a history of smoking ≥ 20 packs of cigarettes per year.^{1,12,18,31,32} The nicotine and thousands of other chemicals present in cigarettes trigger keratinocytes and fibroblasts, resulting in epidermal hyperplasia, infundibular hyperkeratosis, excessive cornification, and dysbiosis.^8,23,24

Hormones. The exact role sex hormones play in the pathogenesis of HS remains unclear.^8,32 Most information is based primarily on small studies looking at antiandrogen treatments, HS activity during the menstrual cycle and pregnancy, HS exacerbation related to androgenic effects of hormonal contraception, and the association of HS with metabolic-endocrine disorders (eg, polycystic ovary syndrome [PCOS]).^8,33

A family history of hidradenitis suppurativa is associated with earlier onset, longer disease duration, and severe disease.

Androgens induce hyperkeratosis that may lead to follicular occlusion—the hallmark of HS pathology.³⁴ A systematic review looking at the role of androgen and estrogen in HS found that while some patients with HS have elevated androgen levels, most have androgen and estrogen levels within normal range.³⁵ Therefore, increased peripheral androgen receptor sensitivity has been hypothesized as the mechanism of action contributing to HS manifestation.³⁴

Continue to: Host-defense defects

Host-defense defects. HS shares a similar cytokine profile with other well-­established immune-mediated inflammatory diseases, including pyoderma gangrenosum (PG)^36,37 and Crohn disease.^38-40 HS is characterized by the expression of several immune mediators, including tumor necrosis factor-alpha (TNF-alpha), interleukin-1 ­alpha (IL-1 alpha), IL-1 beta, IL-8, IL-17, and the IL-23/T helper 17 pathway, all of which are upregulated in other inflammatory diseases and also result in an abnormal innate immune response.^8,24 The recently described clinical triad of PG, acne, and HS (PASH) and the tetrad of pyogenic arthritis, PG, acne, and HS (PAPASH) further support the role of immune dysregulation in the pathogenesis of HS.⁴⁰ Nonetheless, further studies are needed to determine the exact pathways of cytokine effect in HS.⁴¹

Use these criteria to make the diagnosis

The US and Canadian Hidradenitis Suppurativa Foundations (HSF) guidelines base the clinical diagnosis of HS on the following criteria²:

• Typical HS lesions: Erythematous skin lesions; inflamed, deep-seated painful nodules; “tombstone” double-ended comedones; sinus tracts; scarring; deformity. FIGURES 1A-1E show typical lesions seen in patients with HS.
• Typical locations: Intertriginous regions—apocrine gland–containing areas in axilla, groin, perineal region, buttocks, gluteal cleft, and mammary folds; beltline and waistband areas; areas of skin compression and friction.
• Recurrence and chronicity: Recurrent painful or suppurating lesions that appear more than twice in a 6-month period.^2,41-43

Patients with HS usually present with painful recurrent abscesses and scarring and often report multiple visits to the emergency department for drainage or failed antibiotic treatment for abscesses.^15,44

Ask patients these 2 questions. Vinding et al⁴⁵ developed a survey for the diagnosis of HS using 2 simple questions based on the 3 criteria established by the HSF:

1. “Have you had an outbreak of boils during the last 6 months?” and
2. “Where and how many boils have you had?” (This question includes a list of the typical HS locations—eg, axilla, groin, genitals, area under breast.)

In their questionnaire, Vinding et al⁴⁵ found that an affirmative answer to Question 1 and reports of > 2 boils in response to Question 2 correlated to a sensitivity of 90%, specificity of 97%, positive predictive value of 96%, and negative predictive value of 92% for the diagnosis of HS. The differential diagnosis of HS is summarized in TABLE 1.^42,45-52

Continue to: These tools can help you to stage hidradenitis suppurativa

Multiple tools are available to assess the severity of HS.⁵³ We will describe the Hurley staging system and the International Hidradenitis Suppurativa Severity Score System (IHS4). Other diagnostic tools, such as the Sartorius score and the Hidradenitis Suppurativa Physician’s Global Assessment Scale (HS-PGA), can be time-consuming and challenging to interpret, limiting their use in the clinical setting.^2,54

Hurley staging system (available at www.hsdiseasesource.com/hs-disease-­staging) considers the presence of nodules, abscesses, sinus tracts, and scarring affecting an entire anatomical area.^13,55 This system is most useful as a rapid classification tool for patients with HS in the clinical setting but should not be used to assess clinical response.^2,13,56

The IHS4 (available at https://online­ library.wiley.com/doi/10.1111/bjd.15748) is a validated and easy-to-use tool for assessing HS and guiding the therapeutic strategy in clinical practice.⁵⁴ With IHS4, the clinician must calculate the following:

• total number of nodules > 10 mm in diameter
• total number of abscesses multiplied by 2, and
• total number of draining tunnels (fistulae/sinuses) multiplied by 4.

Mild HS is defined as a score ≤ 3 points; moderate HS, 4 to 10 points; and severe HS, ≥ 11 points.⁵⁴

No diagnostic tests, but ultrasound may be helpful

There are currently no established biological markers or specific tests for diagnosing HS.¹⁵ Ultrasound is emerging as a tool to assess dermal thickness, hair follicle morphology, and number and extent of fluid collections. Two recent studies showed that pairing clinical assessment with ultrasound findings improves accuracy of scoring in 84% of cases.^57,58 For patients with severe HS, skin biopsy can be considered to rule out squamous cell carcinoma. Cultures, however, have limited utility except for suspected superimposed bacterial infection.²

Continue to: Screening for comorbidities

Screening for comorbidities

HSF recommends clinicians screen patients for comorbidities associated with HS (TABLE 2).² Overall, screening patients for active and past history of smoking is strongly recommended, as is screening for metabolic syndrome, hyperlipidemia, type 2 diabetes (1.5- to 3-fold greater risk of type 2 diabetes in HS patients), and PCOS (3-fold greater risk).^2,26,27,59 Screening patients for depression and anxiety is also routinely recommended.² However, the authors of this article strongly recommend screening all patients with HS for psychiatric comorbidities, as research has shown a 2-fold greater risk of depression and anxiety, social isolation, and low self-esteem that severely limits quality of life (QOL) in this patient population.^60,61

Management

Treat existing lesions, reduce formation of new ones

The main goals of treatment for patients with HS are to treat existing lesions and reduce associated symptoms, reduce the formation of new lesions, and minimize associated psychological morbidity.¹⁵ FPs play an important role in the early diagnosis, treatment, and comprehensive care of patients with HS. This includes monitoring patients, managing comorbidities, making appropriate referrals to dermatologists, and coordinating the multidisciplinary care that patients with HS require.

As many as 90% of patients with hidradenitis suppurativa have a history of smoking ≥ 20 packs of cigarettes per year.

A systematic review identified more than 50 interventions used to treat HS, most based on small observational studies and randomized controlled trials (RCTs) with a high risk of bias.⁶² FIGURE 2^2,62-69 provides an evidence-based treatment algorithm for HS, and TABLE 3^{2,63,64,70-75} summarizes the most commonly used treatments.

Biologic agents

Adalimumab (ADA) is a fully human immunoglobulin G1 monoclonal antibody that binds to TNF-alpha, neutralizes its bioactivity, and induces apoptosis of TNF-expressing mononuclear cells. It is the only medication approved by the US Food and Drug Administration for active refractory moderate and severe HS.^62,65 Several double-blinded RCTs, including PIONEER I and PIONEER II, studied the effectiveness of ADA for HS and found significant clinical responses at Week 12, 50% reduction in abscess and nodule counts, no increase in abscesses or draining fistulas at Week 12, and sustained improvement in lesion counts, pain, and QOL.^66,67,76

IL-1 and IL-23 inhibitors. The efficacy of etanercept and golimumab (anti-TNF), as well as anakinra (IL-1 inhibitor) and ustekinumab (IL-1/IL-23 inhibitor), continue to be investigated with variable results; they are considered second-line treatment for active refractory moderate and severe HS after ADA.^65,77-80 In­fliximab (IL-1 beta inhibitor) has shown no effect on reducing disease severity.⁷⁰Compared to other treatments, biologic therapy is associated with higher costs (TABLE 3),^{2,63,64,70-75} an increased risk for reactivation of latent infections (eg, tuberculosis, herpes simplex, and hepatitis C virus [HCV], and B [HBV]), and an attenuated response to vaccines.⁸¹ Prior to starting biologic therapy, FPs should screen patients with HS for tuberculosis and HBV, consider HIV and HCV screening in at-risk patients, and optimize the immunization status of the patient.^82,83 While inactivated vaccines can be administered without discontinuing biologic treatment, patients should avoid live-attenuated vaccines while taking biologics.⁸³

Continue to: Antibiotic therapy

Topical antibiotics are considered first-line treatment for mild and moderate uncomplicated HS.^63,64 Clindamycin 1%, the only topical antibiotic studied in a small double-blind RCT of patients with Hurley stage I and stage II HS, demonstrated significant clinical improvement after 12 weeks of treatment (twice- daily application), compared to placebo.⁸⁴ Topical clindamycin is also recommended to treat flares in patients with mild disease.^2,64

Oral antibiotics. Tetracycline (500 mg twice daily for 4 months) is considered a second-line treatment for patients with mild HS.^64,68 Doxycycline (200 mg/d for 3 months) may also be considered as a second-line treatment in patients with mild disease.⁸⁵

All patients with hidradenitis suppurativa should be screened for depression, anxiety, social isolation, and low self-esteem.

Combination oral clindamycin (300 mg) and rifampicin (300 mg) twice daily for 10 weeks is recommended as first-line treatment for patients with moderate HS.^2,64,69 Combination rifampin (300 mg twice daily), moxifloxacin (400 mg/d), and metronidazole (500 mg three times a day) is not routinely recommended due to increased risk of ­toxicity.²

Ertapenem (1 g intravenously daily for 6 weeks) is supported by lower-level evidence as a third-line rescue therapy option and as a bridge to surgery; however, limitations for home infusions, costs, and concerns for antibiotic resistance limit its use.^2,86

Corticosteroids and systemic immunomodulators

Intralesional triamcinolone (2-20 mg) may be beneficial in the early stages of HS, although its use is based on a small prospective open study of 33 patients.⁸⁷ A recent double-blind placebo-controlled RCT comparing varying concentrations of intralesional triamcinolone (10 mg/mL and 40 mg/mL) vs normal saline showed no statistically significant difference in inflammatory clearance, pain reduction, or patient satisfaction.⁸⁸

Continue to: Short-term systemic corticosteroid tapers...

Short-term systemic corticosteroid tapers (eg, prednisone, starting at 0.5-1 mg/kg) are recommended to treat flares. Long-term corticosteroids and cyclosporine are reserved for patients with severe refractory disease; however, due to safety concerns, their regular use is strongly discouraged.^63,64,85 There is limited evidence to support the use of methotrexate for severe refractory disease, and its use is not recommended.⁶³

Hormonal therapy

The use of hormonal therapy for HS is limited by the low-quality evidence (eg, anecdotal evidence, small retrospective analyses, uncontrolled trials).^33,63 The only exception is a small double-blind controlled crossover trial from 1986 showing that the antiandrogen effects of combination oral contraceptives (ethinyloestradiol 50 mcg/cyproterone acetate in a reverse sequential regimen and ethinyloestradiol 50 mcg/norgestrel 500 mcg) improved HS lesions.⁸⁹

Spironolactone, an antiandrogen diuretic, has been studied in small case report series with a high risk for bias. It is used mainly in female patients with mild or moderate disease, or in combination with other agents in patients with severe HS. Further research is needed to determine its utility in the treatment of HS.^63,90,91

Metformin, alone or in combination with other therapies (dapsone, finasteride, liraglutide), has been analyzed in small prospective studies of primarily female patients with different severities of HS, obesity, and PCOS. These studies have shown improvement in lesions, QOL, and reduction of workdays lost.^92,93

Finasteride. Studies have shown finasteride (1.25-5 mg/d) alone or in combination with other treatments (metformin, liraglutide, levonorgestrel-ethinyl estradiol, and dapsone) provided varying degrees of resolution or improvement in patients with severe and advanced HS. Finasteride has been used for 4 to 16 weeks with a good safety profile.^92,94-96

Continue to: Retinoids

Acitretin, alitretinoin, and isotretinoin have been studied in small retrospective studies to manage HS, with variable results.^97-99 Robust prospective studies are needed. Retinoids, in general, should be considered as a second- or third-line treatment for moderate to severe HS.⁶³

Surgical intervention

Surgical interventions, which should be considered in patients with widespread mild, moderate, or severe disease, are associated with improved daily activity and work productivity.¹⁰⁰ Incision and drainage should be avoided in patients with HS, as this technique does not remove the affected follicles and is associated with 100% recurrence.¹⁰¹

Wide excision is the preferred surgical technique for patients with Hurley stage II and stage III HS; it is associated with lower recurrence rates (13%) compared to local excision (22%) and deroofing (27%).¹⁰² Secondary intention healing is the most commonly chosen method, based on lower recurrence rates than primary closure.¹⁰²

STEEP and laser techniques. The skin-tissue-sparing excision with electrosurgical peeling (STEEP) procedure involves successive tangential excision of affected tissue until the epithelized bottom of the sinus tracts has been reached. This allows for the removal of fibrotic tissue and the sparing of the deep subcutaneous fat. STEEP is associated with 30% of relapses after 43 months.⁷¹

When considering biologic therapy, screen all patients with hidradenitis suppurativa for tuberculosis and hepatitis B, and confirm they are current with age-appropriate immunizations.

Laser surgery has also been studied in patients with Hurley stage II and stage III HS. The most commonly used lasers for HS are the 1064-nm neodymium-doped yttrium aluminum garnet (Nd: YAG) and the carbon dioxide laser; they have been shown to reduce disease severity in inguinal, axillary, and inflammatory sites.^72-74

Pain management: Start with lidocaine, NSAIDs

There are few studies about HS-associated pain management.¹⁰³ For acute episodes, short-acting nonopioid local treatment with lidocaine, topical or oral nonsteroidal anti-inflammatory drugs, and acetaminophen are preferred. Opioids should be reserved for moderate-to-severe pain that has not responded to other analgesics. Adjuvant therapy with pregabalin, gabapentin, selective serotonin reuptake inhibitors, or serotonin-norepinephrine reuptake inhibitors can also be considered for the comanagement of pain and depression.^62,104

Consider this tool to measure treatment response

The HS clinical response (HiSCR) tool is an outcome measure used to evaluate treatment outcomes. The tool uses an HS-specific binary score with the following criteria:

1. ≥ 50% reduction in the number of inflammatory nodules;
2. no increase in the number of abscesses; and
3. no increase in the number of draining fistulas.¹⁰⁵

The HiSCR was developed for the ­PIONEER studies^105,106 to assess the response to ADA treatment. It is the only HS scoring system to undergo an extensive validation process with a meaningful clinical endpoint for HS treatment evaluation that is easy to use. Compared to the HS-PGA score (clear, minimal, mild), HiSCR was more responsive to change in patients with HS.^105,106 

CORRESPONDENCE
Cristina Marti-Amarista, MD, 101 Nicolls Road, Stony Brook, NY, 11794-8228; marti.amarista@gmail.com

Hidradenitis suppurativa (HS), also known as acne inversa or Verneuil disease, is a chronic, recurrent, inflammatory occlusive disease affecting the terminal follicular epithelium in apocrine gland–bearing skin areas.¹ HS manifests as painful nodules, abscesses, fistulas, and scarring and often has a severe psychological impact on the affected patient.²

When HS was first identified in the 1800s, it was believed to result from a dysfunction of the sweat glands.³ In 1939, scientists identified the true cause: follicular occlusion.³

Due to its chronic nature, heterogeneity in presentation, and apparent low prevalence,⁴ HS is considered an orphan disease.⁵ Over the past 10 years, there has been a surge in HS research—particularly in medical management—which has provided a better understanding of this condition.^6,7

In this review, we discuss the most updated evidence regarding the diagnosis and treatment of HS to guide the family physician (FP)’s approach to managing this debilitating disease. But first, we offer a word about the etiology and pathophysiology of the condition.

3 events set the stage for hidradenitis suppurativa

Although the exact cause of HS is still unknown, some researchers have hypothesized that HS results from a combination of genetic predisposition and environmental and lifestyle factors.^8-12 The primary mechanism of HS is the obstruction of the terminal follicular epithelium by a keratin plug.^1,13,14 A systematic review of molecular inflammatory pathways involved in HS divides the pathogenesis of HS into 3 events: follicular occlusion followed by dilation, follicular rupture and inflammatory response, and chronic inflammatory state with sinus tracts.⁸

An underreported condition

HS is often underreported and misdiagnosed.^4,15 Globally, the prevalence of HS varies from < 1% to 4%.^15,16 A systematic review with meta-analysis showed a higher prevalence of HS in females compared to males in American and European populations.¹⁷ In the United States, the overall frequency of HS is 0.1%, or 98 per 100,000 persons.¹⁶ The prevalence of HS is highest among patients ages 30 to 39 years; there is decreased prevalence in patients ages 55 years and older.^16,18

Who is at heightened risk?

Recent research has shown a relationship between ethnicity and HS.^16,19,20 African American and biracial groups (defined as African American and White) have a 3-fold and 2-fold greater prevalence of HS, respectively, compared to White patients.¹⁶ However, the prevalence of HS in non-White ethnic groups may be underestimated in clinical trials due to a lack of representation and subgroup analyses based on ethnicity, which may affect generalizability in HS recommendations.²¹

Continue to: Genetic predisposition

Genetic predisposition. As many as 40% of patients with HS report having at least 1 affected family member. A positive family history of HS is associated with earlier onset, longer disease duration, and severe disease.²² HS is genetically heterogeneous, and several mutations (eg, gamma secretase, PSTPIP1, PSEN1 genes) have been identified in patients and in vitro as the cause of dysregulation of epidermal proliferation and differentiation, immune dysregulation, and promotion of amyloid formation.^8,23-25

Obesity and metabolic risk factors. There is a strong relationship between HS and obesity. As many as 70% of patients with HS are obese, and 9% to 40% have metabolic syndrome.^12,18,26-28 Obesity is associated with maceration and mechanical stress, increased fragility of the dermo-epidermal junction, changes in cutaneous blood flow, and subdermal fat inflammation—all of which favor the pathophysiology of HS.^29,30

Smoking. Tobacco smoking is associated with severe HS and a lower chance of remission.¹² Population-based studies have shown that as many as 90% of patients with HS have a history of smoking ≥ 20 packs of cigarettes per year.^{1,12,18,31,32} The nicotine and thousands of other chemicals present in cigarettes trigger keratinocytes and fibroblasts, resulting in epidermal hyperplasia, infundibular hyperkeratosis, excessive cornification, and dysbiosis.^8,23,24

Hormones. The exact role sex hormones play in the pathogenesis of HS remains unclear.^8,32 Most information is based primarily on small studies looking at antiandrogen treatments, HS activity during the menstrual cycle and pregnancy, HS exacerbation related to androgenic effects of hormonal contraception, and the association of HS with metabolic-endocrine disorders (eg, polycystic ovary syndrome [PCOS]).^8,33

A family history of hidradenitis suppurativa is associated with earlier onset, longer disease duration, and severe disease.

Androgens induce hyperkeratosis that may lead to follicular occlusion—the hallmark of HS pathology.³⁴ A systematic review looking at the role of androgen and estrogen in HS found that while some patients with HS have elevated androgen levels, most have androgen and estrogen levels within normal range.³⁵ Therefore, increased peripheral androgen receptor sensitivity has been hypothesized as the mechanism of action contributing to HS manifestation.³⁴

Continue to: Host-defense defects

Host-defense defects. HS shares a similar cytokine profile with other well-­established immune-mediated inflammatory diseases, including pyoderma gangrenosum (PG)^36,37 and Crohn disease.^38-40 HS is characterized by the expression of several immune mediators, including tumor necrosis factor-alpha (TNF-alpha), interleukin-1 ­alpha (IL-1 alpha), IL-1 beta, IL-8, IL-17, and the IL-23/T helper 17 pathway, all of which are upregulated in other inflammatory diseases and also result in an abnormal innate immune response.^8,24 The recently described clinical triad of PG, acne, and HS (PASH) and the tetrad of pyogenic arthritis, PG, acne, and HS (PAPASH) further support the role of immune dysregulation in the pathogenesis of HS.⁴⁰ Nonetheless, further studies are needed to determine the exact pathways of cytokine effect in HS.⁴¹

Use these criteria to make the diagnosis

The US and Canadian Hidradenitis Suppurativa Foundations (HSF) guidelines base the clinical diagnosis of HS on the following criteria²:

• Typical HS lesions: Erythematous skin lesions; inflamed, deep-seated painful nodules; “tombstone” double-ended comedones; sinus tracts; scarring; deformity. FIGURES 1A-1E show typical lesions seen in patients with HS.
• Typical locations: Intertriginous regions—apocrine gland–containing areas in axilla, groin, perineal region, buttocks, gluteal cleft, and mammary folds; beltline and waistband areas; areas of skin compression and friction.
• Recurrence and chronicity: Recurrent painful or suppurating lesions that appear more than twice in a 6-month period.^2,41-43

Patients with HS usually present with painful recurrent abscesses and scarring and often report multiple visits to the emergency department for drainage or failed antibiotic treatment for abscesses.^15,44

Ask patients these 2 questions. Vinding et al⁴⁵ developed a survey for the diagnosis of HS using 2 simple questions based on the 3 criteria established by the HSF:

1. “Have you had an outbreak of boils during the last 6 months?” and
2. “Where and how many boils have you had?” (This question includes a list of the typical HS locations—eg, axilla, groin, genitals, area under breast.)

In their questionnaire, Vinding et al⁴⁵ found that an affirmative answer to Question 1 and reports of > 2 boils in response to Question 2 correlated to a sensitivity of 90%, specificity of 97%, positive predictive value of 96%, and negative predictive value of 92% for the diagnosis of HS. The differential diagnosis of HS is summarized in TABLE 1.^42,45-52

Continue to: These tools can help you to stage hidradenitis suppurativa

Multiple tools are available to assess the severity of HS.⁵³ We will describe the Hurley staging system and the International Hidradenitis Suppurativa Severity Score System (IHS4). Other diagnostic tools, such as the Sartorius score and the Hidradenitis Suppurativa Physician’s Global Assessment Scale (HS-PGA), can be time-consuming and challenging to interpret, limiting their use in the clinical setting.^2,54

Hurley staging system (available at www.hsdiseasesource.com/hs-disease-­staging) considers the presence of nodules, abscesses, sinus tracts, and scarring affecting an entire anatomical area.^13,55 This system is most useful as a rapid classification tool for patients with HS in the clinical setting but should not be used to assess clinical response.^2,13,56

The IHS4 (available at https://online­ library.wiley.com/doi/10.1111/bjd.15748) is a validated and easy-to-use tool for assessing HS and guiding the therapeutic strategy in clinical practice.⁵⁴ With IHS4, the clinician must calculate the following:

• total number of nodules > 10 mm in diameter
• total number of abscesses multiplied by 2, and
• total number of draining tunnels (fistulae/sinuses) multiplied by 4.

Mild HS is defined as a score ≤ 3 points; moderate HS, 4 to 10 points; and severe HS, ≥ 11 points.⁵⁴

No diagnostic tests, but ultrasound may be helpful

There are currently no established biological markers or specific tests for diagnosing HS.¹⁵ Ultrasound is emerging as a tool to assess dermal thickness, hair follicle morphology, and number and extent of fluid collections. Two recent studies showed that pairing clinical assessment with ultrasound findings improves accuracy of scoring in 84% of cases.^57,58 For patients with severe HS, skin biopsy can be considered to rule out squamous cell carcinoma. Cultures, however, have limited utility except for suspected superimposed bacterial infection.²

Continue to: Screening for comorbidities

Screening for comorbidities

HSF recommends clinicians screen patients for comorbidities associated with HS (TABLE 2).² Overall, screening patients for active and past history of smoking is strongly recommended, as is screening for metabolic syndrome, hyperlipidemia, type 2 diabetes (1.5- to 3-fold greater risk of type 2 diabetes in HS patients), and PCOS (3-fold greater risk).^2,26,27,59 Screening patients for depression and anxiety is also routinely recommended.² However, the authors of this article strongly recommend screening all patients with HS for psychiatric comorbidities, as research has shown a 2-fold greater risk of depression and anxiety, social isolation, and low self-esteem that severely limits quality of life (QOL) in this patient population.^60,61

Management

Treat existing lesions, reduce formation of new ones

The main goals of treatment for patients with HS are to treat existing lesions and reduce associated symptoms, reduce the formation of new lesions, and minimize associated psychological morbidity.¹⁵ FPs play an important role in the early diagnosis, treatment, and comprehensive care of patients with HS. This includes monitoring patients, managing comorbidities, making appropriate referrals to dermatologists, and coordinating the multidisciplinary care that patients with HS require.

As many as 90% of patients with hidradenitis suppurativa have a history of smoking ≥ 20 packs of cigarettes per year.

A systematic review identified more than 50 interventions used to treat HS, most based on small observational studies and randomized controlled trials (RCTs) with a high risk of bias.⁶² FIGURE 2^2,62-69 provides an evidence-based treatment algorithm for HS, and TABLE 3^{2,63,64,70-75} summarizes the most commonly used treatments.

Biologic agents

Adalimumab (ADA) is a fully human immunoglobulin G1 monoclonal antibody that binds to TNF-alpha, neutralizes its bioactivity, and induces apoptosis of TNF-expressing mononuclear cells. It is the only medication approved by the US Food and Drug Administration for active refractory moderate and severe HS.^62,65 Several double-blinded RCTs, including PIONEER I and PIONEER II, studied the effectiveness of ADA for HS and found significant clinical responses at Week 12, 50% reduction in abscess and nodule counts, no increase in abscesses or draining fistulas at Week 12, and sustained improvement in lesion counts, pain, and QOL.^66,67,76

IL-1 and IL-23 inhibitors. The efficacy of etanercept and golimumab (anti-TNF), as well as anakinra (IL-1 inhibitor) and ustekinumab (IL-1/IL-23 inhibitor), continue to be investigated with variable results; they are considered second-line treatment for active refractory moderate and severe HS after ADA.^65,77-80 In­fliximab (IL-1 beta inhibitor) has shown no effect on reducing disease severity.⁷⁰Compared to other treatments, biologic therapy is associated with higher costs (TABLE 3),^{2,63,64,70-75} an increased risk for reactivation of latent infections (eg, tuberculosis, herpes simplex, and hepatitis C virus [HCV], and B [HBV]), and an attenuated response to vaccines.⁸¹ Prior to starting biologic therapy, FPs should screen patients with HS for tuberculosis and HBV, consider HIV and HCV screening in at-risk patients, and optimize the immunization status of the patient.^82,83 While inactivated vaccines can be administered without discontinuing biologic treatment, patients should avoid live-attenuated vaccines while taking biologics.⁸³

Continue to: Antibiotic therapy

Topical antibiotics are considered first-line treatment for mild and moderate uncomplicated HS.^63,64 Clindamycin 1%, the only topical antibiotic studied in a small double-blind RCT of patients with Hurley stage I and stage II HS, demonstrated significant clinical improvement after 12 weeks of treatment (twice- daily application), compared to placebo.⁸⁴ Topical clindamycin is also recommended to treat flares in patients with mild disease.^2,64

Oral antibiotics. Tetracycline (500 mg twice daily for 4 months) is considered a second-line treatment for patients with mild HS.^64,68 Doxycycline (200 mg/d for 3 months) may also be considered as a second-line treatment in patients with mild disease.⁸⁵

All patients with hidradenitis suppurativa should be screened for depression, anxiety, social isolation, and low self-esteem.

Combination oral clindamycin (300 mg) and rifampicin (300 mg) twice daily for 10 weeks is recommended as first-line treatment for patients with moderate HS.^2,64,69 Combination rifampin (300 mg twice daily), moxifloxacin (400 mg/d), and metronidazole (500 mg three times a day) is not routinely recommended due to increased risk of ­toxicity.²

Ertapenem (1 g intravenously daily for 6 weeks) is supported by lower-level evidence as a third-line rescue therapy option and as a bridge to surgery; however, limitations for home infusions, costs, and concerns for antibiotic resistance limit its use.^2,86

Corticosteroids and systemic immunomodulators

Intralesional triamcinolone (2-20 mg) may be beneficial in the early stages of HS, although its use is based on a small prospective open study of 33 patients.⁸⁷ A recent double-blind placebo-controlled RCT comparing varying concentrations of intralesional triamcinolone (10 mg/mL and 40 mg/mL) vs normal saline showed no statistically significant difference in inflammatory clearance, pain reduction, or patient satisfaction.⁸⁸

Continue to: Short-term systemic corticosteroid tapers...

Short-term systemic corticosteroid tapers (eg, prednisone, starting at 0.5-1 mg/kg) are recommended to treat flares. Long-term corticosteroids and cyclosporine are reserved for patients with severe refractory disease; however, due to safety concerns, their regular use is strongly discouraged.^63,64,85 There is limited evidence to support the use of methotrexate for severe refractory disease, and its use is not recommended.⁶³

Hormonal therapy

The use of hormonal therapy for HS is limited by the low-quality evidence (eg, anecdotal evidence, small retrospective analyses, uncontrolled trials).^33,63 The only exception is a small double-blind controlled crossover trial from 1986 showing that the antiandrogen effects of combination oral contraceptives (ethinyloestradiol 50 mcg/cyproterone acetate in a reverse sequential regimen and ethinyloestradiol 50 mcg/norgestrel 500 mcg) improved HS lesions.⁸⁹

Spironolactone, an antiandrogen diuretic, has been studied in small case report series with a high risk for bias. It is used mainly in female patients with mild or moderate disease, or in combination with other agents in patients with severe HS. Further research is needed to determine its utility in the treatment of HS.^63,90,91

Metformin, alone or in combination with other therapies (dapsone, finasteride, liraglutide), has been analyzed in small prospective studies of primarily female patients with different severities of HS, obesity, and PCOS. These studies have shown improvement in lesions, QOL, and reduction of workdays lost.^92,93

Finasteride. Studies have shown finasteride (1.25-5 mg/d) alone or in combination with other treatments (metformin, liraglutide, levonorgestrel-ethinyl estradiol, and dapsone) provided varying degrees of resolution or improvement in patients with severe and advanced HS. Finasteride has been used for 4 to 16 weeks with a good safety profile.^92,94-96

Continue to: Retinoids

Acitretin, alitretinoin, and isotretinoin have been studied in small retrospective studies to manage HS, with variable results.^97-99 Robust prospective studies are needed. Retinoids, in general, should be considered as a second- or third-line treatment for moderate to severe HS.⁶³

Surgical intervention

Surgical interventions, which should be considered in patients with widespread mild, moderate, or severe disease, are associated with improved daily activity and work productivity.¹⁰⁰ Incision and drainage should be avoided in patients with HS, as this technique does not remove the affected follicles and is associated with 100% recurrence.¹⁰¹

Wide excision is the preferred surgical technique for patients with Hurley stage II and stage III HS; it is associated with lower recurrence rates (13%) compared to local excision (22%) and deroofing (27%).¹⁰² Secondary intention healing is the most commonly chosen method, based on lower recurrence rates than primary closure.¹⁰²

STEEP and laser techniques. The skin-tissue-sparing excision with electrosurgical peeling (STEEP) procedure involves successive tangential excision of affected tissue until the epithelized bottom of the sinus tracts has been reached. This allows for the removal of fibrotic tissue and the sparing of the deep subcutaneous fat. STEEP is associated with 30% of relapses after 43 months.⁷¹

When considering biologic therapy, screen all patients with hidradenitis suppurativa for tuberculosis and hepatitis B, and confirm they are current with age-appropriate immunizations.

Laser surgery has also been studied in patients with Hurley stage II and stage III HS. The most commonly used lasers for HS are the 1064-nm neodymium-doped yttrium aluminum garnet (Nd: YAG) and the carbon dioxide laser; they have been shown to reduce disease severity in inguinal, axillary, and inflammatory sites.^72-74

Pain management: Start with lidocaine, NSAIDs

There are few studies about HS-associated pain management.¹⁰³ For acute episodes, short-acting nonopioid local treatment with lidocaine, topical or oral nonsteroidal anti-inflammatory drugs, and acetaminophen are preferred. Opioids should be reserved for moderate-to-severe pain that has not responded to other analgesics. Adjuvant therapy with pregabalin, gabapentin, selective serotonin reuptake inhibitors, or serotonin-norepinephrine reuptake inhibitors can also be considered for the comanagement of pain and depression.^62,104

Consider this tool to measure treatment response

The HS clinical response (HiSCR) tool is an outcome measure used to evaluate treatment outcomes. The tool uses an HS-specific binary score with the following criteria:

1. ≥ 50% reduction in the number of inflammatory nodules;
2. no increase in the number of abscesses; and
3. no increase in the number of draining fistulas.¹⁰⁵

The HiSCR was developed for the ­PIONEER studies^105,106 to assess the response to ADA treatment. It is the only HS scoring system to undergo an extensive validation process with a meaningful clinical endpoint for HS treatment evaluation that is easy to use. Compared to the HS-PGA score (clear, minimal, mild), HiSCR was more responsive to change in patients with HS.^105,106 

CORRESPONDENCE
Cristina Marti-Amarista, MD, 101 Nicolls Road, Stony Brook, NY, 11794-8228; marti.amarista@gmail.com

Hidradenitis suppurativa (HS), also known as acne inversa or Verneuil disease, is a chronic, recurrent, inflammatory occlusive disease affecting the terminal follicular epithelium in apocrine gland–bearing skin areas.¹ HS manifests as painful nodules, abscesses, fistulas, and scarring and often has a severe psychological impact on the affected patient.²

When HS was first identified in the 1800s, it was believed to result from a dysfunction of the sweat glands.³ In 1939, scientists identified the true cause: follicular occlusion.³

Due to its chronic nature, heterogeneity in presentation, and apparent low prevalence,⁴ HS is considered an orphan disease.⁵ Over the past 10 years, there has been a surge in HS research—particularly in medical management—which has provided a better understanding of this condition.^6,7

In this review, we discuss the most updated evidence regarding the diagnosis and treatment of HS to guide the family physician (FP)’s approach to managing this debilitating disease. But first, we offer a word about the etiology and pathophysiology of the condition.

3 events set the stage for hidradenitis suppurativa

Although the exact cause of HS is still unknown, some researchers have hypothesized that HS results from a combination of genetic predisposition and environmental and lifestyle factors.^8-12 The primary mechanism of HS is the obstruction of the terminal follicular epithelium by a keratin plug.^1,13,14 A systematic review of molecular inflammatory pathways involved in HS divides the pathogenesis of HS into 3 events: follicular occlusion followed by dilation, follicular rupture and inflammatory response, and chronic inflammatory state with sinus tracts.⁸

An underreported condition

HS is often underreported and misdiagnosed.^4,15 Globally, the prevalence of HS varies from < 1% to 4%.^15,16 A systematic review with meta-analysis showed a higher prevalence of HS in females compared to males in American and European populations.¹⁷ In the United States, the overall frequency of HS is 0.1%, or 98 per 100,000 persons.¹⁶ The prevalence of HS is highest among patients ages 30 to 39 years; there is decreased prevalence in patients ages 55 years and older.^16,18

Who is at heightened risk?

Recent research has shown a relationship between ethnicity and HS.^16,19,20 African American and biracial groups (defined as African American and White) have a 3-fold and 2-fold greater prevalence of HS, respectively, compared to White patients.¹⁶ However, the prevalence of HS in non-White ethnic groups may be underestimated in clinical trials due to a lack of representation and subgroup analyses based on ethnicity, which may affect generalizability in HS recommendations.²¹

Continue to: Genetic predisposition

Genetic predisposition. As many as 40% of patients with HS report having at least 1 affected family member. A positive family history of HS is associated with earlier onset, longer disease duration, and severe disease.²² HS is genetically heterogeneous, and several mutations (eg, gamma secretase, PSTPIP1, PSEN1 genes) have been identified in patients and in vitro as the cause of dysregulation of epidermal proliferation and differentiation, immune dysregulation, and promotion of amyloid formation.^8,23-25

Obesity and metabolic risk factors. There is a strong relationship between HS and obesity. As many as 70% of patients with HS are obese, and 9% to 40% have metabolic syndrome.^12,18,26-28 Obesity is associated with maceration and mechanical stress, increased fragility of the dermo-epidermal junction, changes in cutaneous blood flow, and subdermal fat inflammation—all of which favor the pathophysiology of HS.^29,30

Smoking. Tobacco smoking is associated with severe HS and a lower chance of remission.¹² Population-based studies have shown that as many as 90% of patients with HS have a history of smoking ≥ 20 packs of cigarettes per year.^{1,12,18,31,32} The nicotine and thousands of other chemicals present in cigarettes trigger keratinocytes and fibroblasts, resulting in epidermal hyperplasia, infundibular hyperkeratosis, excessive cornification, and dysbiosis.^8,23,24

Hormones. The exact role sex hormones play in the pathogenesis of HS remains unclear.^8,32 Most information is based primarily on small studies looking at antiandrogen treatments, HS activity during the menstrual cycle and pregnancy, HS exacerbation related to androgenic effects of hormonal contraception, and the association of HS with metabolic-endocrine disorders (eg, polycystic ovary syndrome [PCOS]).^8,33

A family history of hidradenitis suppurativa is associated with earlier onset, longer disease duration, and severe disease.

Androgens induce hyperkeratosis that may lead to follicular occlusion—the hallmark of HS pathology.³⁴ A systematic review looking at the role of androgen and estrogen in HS found that while some patients with HS have elevated androgen levels, most have androgen and estrogen levels within normal range.³⁵ Therefore, increased peripheral androgen receptor sensitivity has been hypothesized as the mechanism of action contributing to HS manifestation.³⁴

Continue to: Host-defense defects

Host-defense defects. HS shares a similar cytokine profile with other well-­established immune-mediated inflammatory diseases, including pyoderma gangrenosum (PG)^36,37 and Crohn disease.^38-40 HS is characterized by the expression of several immune mediators, including tumor necrosis factor-alpha (TNF-alpha), interleukin-1 ­alpha (IL-1 alpha), IL-1 beta, IL-8, IL-17, and the IL-23/T helper 17 pathway, all of which are upregulated in other inflammatory diseases and also result in an abnormal innate immune response.^8,24 The recently described clinical triad of PG, acne, and HS (PASH) and the tetrad of pyogenic arthritis, PG, acne, and HS (PAPASH) further support the role of immune dysregulation in the pathogenesis of HS.⁴⁰ Nonetheless, further studies are needed to determine the exact pathways of cytokine effect in HS.⁴¹

Use these criteria to make the diagnosis

The US and Canadian Hidradenitis Suppurativa Foundations (HSF) guidelines base the clinical diagnosis of HS on the following criteria²:

• Typical HS lesions: Erythematous skin lesions; inflamed, deep-seated painful nodules; “tombstone” double-ended comedones; sinus tracts; scarring; deformity. FIGURES 1A-1E show typical lesions seen in patients with HS.
• Typical locations: Intertriginous regions—apocrine gland–containing areas in axilla, groin, perineal region, buttocks, gluteal cleft, and mammary folds; beltline and waistband areas; areas of skin compression and friction.
• Recurrence and chronicity: Recurrent painful or suppurating lesions that appear more than twice in a 6-month period.^2,41-43

Patients with HS usually present with painful recurrent abscesses and scarring and often report multiple visits to the emergency department for drainage or failed antibiotic treatment for abscesses.^15,44

Ask patients these 2 questions. Vinding et al⁴⁵ developed a survey for the diagnosis of HS using 2 simple questions based on the 3 criteria established by the HSF:

1. “Have you had an outbreak of boils during the last 6 months?” and
2. “Where and how many boils have you had?” (This question includes a list of the typical HS locations—eg, axilla, groin, genitals, area under breast.)

In their questionnaire, Vinding et al⁴⁵ found that an affirmative answer to Question 1 and reports of > 2 boils in response to Question 2 correlated to a sensitivity of 90%, specificity of 97%, positive predictive value of 96%, and negative predictive value of 92% for the diagnosis of HS. The differential diagnosis of HS is summarized in TABLE 1.^42,45-52

Continue to: These tools can help you to stage hidradenitis suppurativa

Multiple tools are available to assess the severity of HS.⁵³ We will describe the Hurley staging system and the International Hidradenitis Suppurativa Severity Score System (IHS4). Other diagnostic tools, such as the Sartorius score and the Hidradenitis Suppurativa Physician’s Global Assessment Scale (HS-PGA), can be time-consuming and challenging to interpret, limiting their use in the clinical setting.^2,54

Hurley staging system (available at www.hsdiseasesource.com/hs-disease-­staging) considers the presence of nodules, abscesses, sinus tracts, and scarring affecting an entire anatomical area.^13,55 This system is most useful as a rapid classification tool for patients with HS in the clinical setting but should not be used to assess clinical response.^2,13,56

The IHS4 (available at https://online­ library.wiley.com/doi/10.1111/bjd.15748) is a validated and easy-to-use tool for assessing HS and guiding the therapeutic strategy in clinical practice.⁵⁴ With IHS4, the clinician must calculate the following:

• total number of nodules > 10 mm in diameter
• total number of abscesses multiplied by 2, and
• total number of draining tunnels (fistulae/sinuses) multiplied by 4.

Mild HS is defined as a score ≤ 3 points; moderate HS, 4 to 10 points; and severe HS, ≥ 11 points.⁵⁴

No diagnostic tests, but ultrasound may be helpful

There are currently no established biological markers or specific tests for diagnosing HS.¹⁵ Ultrasound is emerging as a tool to assess dermal thickness, hair follicle morphology, and number and extent of fluid collections. Two recent studies showed that pairing clinical assessment with ultrasound findings improves accuracy of scoring in 84% of cases.^57,58 For patients with severe HS, skin biopsy can be considered to rule out squamous cell carcinoma. Cultures, however, have limited utility except for suspected superimposed bacterial infection.²

Continue to: Screening for comorbidities

Screening for comorbidities

HSF recommends clinicians screen patients for comorbidities associated with HS (TABLE 2).² Overall, screening patients for active and past history of smoking is strongly recommended, as is screening for metabolic syndrome, hyperlipidemia, type 2 diabetes (1.5- to 3-fold greater risk of type 2 diabetes in HS patients), and PCOS (3-fold greater risk).^2,26,27,59 Screening patients for depression and anxiety is also routinely recommended.² However, the authors of this article strongly recommend screening all patients with HS for psychiatric comorbidities, as research has shown a 2-fold greater risk of depression and anxiety, social isolation, and low self-esteem that severely limits quality of life (QOL) in this patient population.^60,61

Management

Treat existing lesions, reduce formation of new ones

The main goals of treatment for patients with HS are to treat existing lesions and reduce associated symptoms, reduce the formation of new lesions, and minimize associated psychological morbidity.¹⁵ FPs play an important role in the early diagnosis, treatment, and comprehensive care of patients with HS. This includes monitoring patients, managing comorbidities, making appropriate referrals to dermatologists, and coordinating the multidisciplinary care that patients with HS require.

As many as 90% of patients with hidradenitis suppurativa have a history of smoking ≥ 20 packs of cigarettes per year.

A systematic review identified more than 50 interventions used to treat HS, most based on small observational studies and randomized controlled trials (RCTs) with a high risk of bias.⁶² FIGURE 2^2,62-69 provides an evidence-based treatment algorithm for HS, and TABLE 3^{2,63,64,70-75} summarizes the most commonly used treatments.

Biologic agents

Adalimumab (ADA) is a fully human immunoglobulin G1 monoclonal antibody that binds to TNF-alpha, neutralizes its bioactivity, and induces apoptosis of TNF-expressing mononuclear cells. It is the only medication approved by the US Food and Drug Administration for active refractory moderate and severe HS.^62,65 Several double-blinded RCTs, including PIONEER I and PIONEER II, studied the effectiveness of ADA for HS and found significant clinical responses at Week 12, 50% reduction in abscess and nodule counts, no increase in abscesses or draining fistulas at Week 12, and sustained improvement in lesion counts, pain, and QOL.^66,67,76

IL-1 and IL-23 inhibitors. The efficacy of etanercept and golimumab (anti-TNF), as well as anakinra (IL-1 inhibitor) and ustekinumab (IL-1/IL-23 inhibitor), continue to be investigated with variable results; they are considered second-line treatment for active refractory moderate and severe HS after ADA.^65,77-80 In­fliximab (IL-1 beta inhibitor) has shown no effect on reducing disease severity.⁷⁰Compared to other treatments, biologic therapy is associated with higher costs (TABLE 3),^{2,63,64,70-75} an increased risk for reactivation of latent infections (eg, tuberculosis, herpes simplex, and hepatitis C virus [HCV], and B [HBV]), and an attenuated response to vaccines.⁸¹ Prior to starting biologic therapy, FPs should screen patients with HS for tuberculosis and HBV, consider HIV and HCV screening in at-risk patients, and optimize the immunization status of the patient.^82,83 While inactivated vaccines can be administered without discontinuing biologic treatment, patients should avoid live-attenuated vaccines while taking biologics.⁸³

Continue to: Antibiotic therapy

Topical antibiotics are considered first-line treatment for mild and moderate uncomplicated HS.^63,64 Clindamycin 1%, the only topical antibiotic studied in a small double-blind RCT of patients with Hurley stage I and stage II HS, demonstrated significant clinical improvement after 12 weeks of treatment (twice- daily application), compared to placebo.⁸⁴ Topical clindamycin is also recommended to treat flares in patients with mild disease.^2,64

Oral antibiotics. Tetracycline (500 mg twice daily for 4 months) is considered a second-line treatment for patients with mild HS.^64,68 Doxycycline (200 mg/d for 3 months) may also be considered as a second-line treatment in patients with mild disease.⁸⁵

All patients with hidradenitis suppurativa should be screened for depression, anxiety, social isolation, and low self-esteem.

Combination oral clindamycin (300 mg) and rifampicin (300 mg) twice daily for 10 weeks is recommended as first-line treatment for patients with moderate HS.^2,64,69 Combination rifampin (300 mg twice daily), moxifloxacin (400 mg/d), and metronidazole (500 mg three times a day) is not routinely recommended due to increased risk of ­toxicity.²

Ertapenem (1 g intravenously daily for 6 weeks) is supported by lower-level evidence as a third-line rescue therapy option and as a bridge to surgery; however, limitations for home infusions, costs, and concerns for antibiotic resistance limit its use.^2,86

Corticosteroids and systemic immunomodulators

Intralesional triamcinolone (2-20 mg) may be beneficial in the early stages of HS, although its use is based on a small prospective open study of 33 patients.⁸⁷ A recent double-blind placebo-controlled RCT comparing varying concentrations of intralesional triamcinolone (10 mg/mL and 40 mg/mL) vs normal saline showed no statistically significant difference in inflammatory clearance, pain reduction, or patient satisfaction.⁸⁸

Continue to: Short-term systemic corticosteroid tapers...

Short-term systemic corticosteroid tapers (eg, prednisone, starting at 0.5-1 mg/kg) are recommended to treat flares. Long-term corticosteroids and cyclosporine are reserved for patients with severe refractory disease; however, due to safety concerns, their regular use is strongly discouraged.^63,64,85 There is limited evidence to support the use of methotrexate for severe refractory disease, and its use is not recommended.⁶³

Hormonal therapy

The use of hormonal therapy for HS is limited by the low-quality evidence (eg, anecdotal evidence, small retrospective analyses, uncontrolled trials).^33,63 The only exception is a small double-blind controlled crossover trial from 1986 showing that the antiandrogen effects of combination oral contraceptives (ethinyloestradiol 50 mcg/cyproterone acetate in a reverse sequential regimen and ethinyloestradiol 50 mcg/norgestrel 500 mcg) improved HS lesions.⁸⁹

Spironolactone, an antiandrogen diuretic, has been studied in small case report series with a high risk for bias. It is used mainly in female patients with mild or moderate disease, or in combination with other agents in patients with severe HS. Further research is needed to determine its utility in the treatment of HS.^63,90,91

Metformin, alone or in combination with other therapies (dapsone, finasteride, liraglutide), has been analyzed in small prospective studies of primarily female patients with different severities of HS, obesity, and PCOS. These studies have shown improvement in lesions, QOL, and reduction of workdays lost.^92,93

Finasteride. Studies have shown finasteride (1.25-5 mg/d) alone or in combination with other treatments (metformin, liraglutide, levonorgestrel-ethinyl estradiol, and dapsone) provided varying degrees of resolution or improvement in patients with severe and advanced HS. Finasteride has been used for 4 to 16 weeks with a good safety profile.^92,94-96

Continue to: Retinoids

Acitretin, alitretinoin, and isotretinoin have been studied in small retrospective studies to manage HS, with variable results.^97-99 Robust prospective studies are needed. Retinoids, in general, should be considered as a second- or third-line treatment for moderate to severe HS.⁶³

Surgical intervention

Surgical interventions, which should be considered in patients with widespread mild, moderate, or severe disease, are associated with improved daily activity and work productivity.¹⁰⁰ Incision and drainage should be avoided in patients with HS, as this technique does not remove the affected follicles and is associated with 100% recurrence.¹⁰¹

Wide excision is the preferred surgical technique for patients with Hurley stage II and stage III HS; it is associated with lower recurrence rates (13%) compared to local excision (22%) and deroofing (27%).¹⁰² Secondary intention healing is the most commonly chosen method, based on lower recurrence rates than primary closure.¹⁰²

STEEP and laser techniques. The skin-tissue-sparing excision with electrosurgical peeling (STEEP) procedure involves successive tangential excision of affected tissue until the epithelized bottom of the sinus tracts has been reached. This allows for the removal of fibrotic tissue and the sparing of the deep subcutaneous fat. STEEP is associated with 30% of relapses after 43 months.⁷¹

When considering biologic therapy, screen all patients with hidradenitis suppurativa for tuberculosis and hepatitis B, and confirm they are current with age-appropriate immunizations.

Laser surgery has also been studied in patients with Hurley stage II and stage III HS. The most commonly used lasers for HS are the 1064-nm neodymium-doped yttrium aluminum garnet (Nd: YAG) and the carbon dioxide laser; they have been shown to reduce disease severity in inguinal, axillary, and inflammatory sites.^72-74

Pain management: Start with lidocaine, NSAIDs

There are few studies about HS-associated pain management.¹⁰³ For acute episodes, short-acting nonopioid local treatment with lidocaine, topical or oral nonsteroidal anti-inflammatory drugs, and acetaminophen are preferred. Opioids should be reserved for moderate-to-severe pain that has not responded to other analgesics. Adjuvant therapy with pregabalin, gabapentin, selective serotonin reuptake inhibitors, or serotonin-norepinephrine reuptake inhibitors can also be considered for the comanagement of pain and depression.^62,104

Consider this tool to measure treatment response

The HS clinical response (HiSCR) tool is an outcome measure used to evaluate treatment outcomes. The tool uses an HS-specific binary score with the following criteria:

1. ≥ 50% reduction in the number of inflammatory nodules;
2. no increase in the number of abscesses; and
3. no increase in the number of draining fistulas.¹⁰⁵

The HiSCR was developed for the ­PIONEER studies^105,106 to assess the response to ADA treatment. It is the only HS scoring system to undergo an extensive validation process with a meaningful clinical endpoint for HS treatment evaluation that is easy to use. Compared to the HS-PGA score (clear, minimal, mild), HiSCR was more responsive to change in patients with HS.^105,106 

CORRESPONDENCE
Cristina Marti-Amarista, MD, 101 Nicolls Road, Stony Brook, NY, 11794-8228; marti.amarista@gmail.com

A 48-YEAR-OLD WOMAN presented to Dermatology for evaluation of a 6-cm abdominal lesion that had been present for 5 weeks ­(FIGURE 1). The lesion was originally about the size of a quarter, but it started to enlarge after treatment of an asthma exacerbation with a 4-day course of prednisone. It continued to grow after another physician, likely presuming the lesion was a corticosteroid-responsive dermatosis (eg, nummular eczema, granuloma annulare, or erythema annulare centrifugum), prescribed a 2-week trial of clobetasol ointment. Physical examination revealed a mildly pruritic, 6-cm erythematous plaque with scaly, annular, concentric rings on the left lower abdomen. The patient had no travel history.

WHAT IS YOUR DIAGNOSIS?
HOW WOULD YOU TREAT THIS PATIENT?

The patient was given a diagnosis of tinea incognito, a form of tinea corporis that is exacerbated by the inappropriate use of corticosteroids in the management of a cutaneous fungal infection.¹ Furthermore, this patient’s case was consistent with tinea pseudoimbricata, a variant of tinea incognito. Tinea pseudoimbricata is characterized by striking concentric scaly rings that mimic tinea imbricata, a fungal infection caused by the dermatophyte Trichophyton concentricum, which is commonly found in tropical areas.²

A common infection is alteredby steroid use

Tinea corporis has a relatively high prevalence. Approximately 10% to 20% of the world population is affected by fungal skin infections.³ 

T rubrum is the most common cause of tinea corporis. Other causes include T tonsurans, T interdigitale, T ­violaceum, Microsporum canis, M gypseum, and M audouinii.

These steroid treatments caused the abdominal lesion to morph from the typical appearance of tinea corporis to an erythematous plaque with striking concentric scaly rings.

Tinea corporis can be acquired through direct contact with an infected person, animal, or fomite. It may also be acquired through autoinoculation from another area of the body containing a dermatophyte fungal infection. Tinea corporis lesions are usually pruritic, erythematous, annular plaques with overlying scale and central clearing.

How steroid use can change the picture. Treatment with corticosteroids is ineffective for fungal skin infections and causes immunosuppression, allowing the fungus to thrive. This patient had been treated with a topical steroid (clobetasol) for the abdominal lesion caused by tinea corporis, as well as an oral steroid (prednisone) for an asthma exacerbation. These steroid treatments caused the abdominal lesion to morph from the typical appearance of tinea corporis—classically an annular erythematous plaque with overlying scale and central clearing—to an erythematous plaque with striking concentric scaly rings.

Continue to: Clinical exam can provide clues; KOH examination can reveal the Dx

The differential diagnosis for an annular skin lesion includes not only tinea corporis, but also superficial erythema annulare centrifugum, pityriasis rosea, granuloma annulare, subacute cutaneous lupus erythematosus (SCLE), and nummular eczema.

Superficial erythema annulare centrifugum, like tinea corporis, has scale. But the location of the scale sets the 2 apart. Superficial erythema annulare centrifugum lesions have a central trailing scale, whereas tinea corporis lesions have a peripheral leading scale.⁴

Pityriasis rosea forms multiple lesions in a “Christmas tree” pattern on the trunk, sometimes beginning with a single herald patch. Our patient’s single lesion with concentric scaly rings was inconsistent with the distribution and quality of the lesions in pityriasis rosea.⁴

Granuloma annulare lesions are smooth, nonscaly plaques that are most often seen on the dorsal hands and feet. The scaly manifestation of our patient’s lesion was not consistent with this diagnosis.⁴

SCLE lesions are typically photodistributed on sun-exposed skin (eg, the neck, upper trunk, or arms), whereas our patient’s lesion involved a sun-protected site.⁴

Continue to: Nummular eczema

Nummular eczema can be differentiated from tinea corporis by potassium hydroxide (KOH) examination. Nummular eczema is characterized by a negative KOH exam and response to topical corticosteroids.⁴

Performing a KOH examination, using the skin scrapings from the active border of a plaque, is useful on any lesion with potential fungal etiology. If the cause is indeed a dermatophyte infection, segmented fungal hyphae will be seen under light microscopy (FIGURE 2).¹ If a KOH examination is not feasible, a skin scraping can be performed with a surgical scalpel blade and collected in a sterile urine cup for stain and culture at a qualified laboratory.

Topical and oral antifungal medications combat dermatophyte fungi

Treatments for cutaneous infections caused by dermatophyte fungi, such as tinea corporis, include topical and oral antifungals. The choice of agent depends on the extent of the disease.

Limited, localized disease can be treated topically with allylamines (terbinafine, naftifine) or imidazoles (clotrimazole). Other topical agents, such as butenafine, ciclopirox, and tolnaftate, also may be used.

Extensive disease, or tinea infection of vellus hairs, may require treatment with oral antifungal medications, such as the azoles (itraconazole, fluconazole), allylamines (terbinafine), or griseofulvin. Systemic therapy with oral antifungals has been associated with liver damage; therefore, oral therapy should not be used in patients with liver disease and liver enzymes should be monitored when appropriate.⁵ Nystatin is not effective in treating dermatophyte fungal infections.¹

One complication of the inappropriate use of steroids on a dermatophyte infection is an increased risk of the fungus extending from the superficial skin into the hair follicles in the dermis, resulting in a condition known as Majocchi granuloma. Follicular infection is more severe and requires oral antifungal medication, such as terbinafine, itraconazole, fluconazole, or griseofulvin.¹

Our patient was treated with terbinafine 250 mg/d for 4 weeks, due to the possibility of follicular infection. After the completion of 4 weeks of therapy, the patient’s cutaneous symptoms had resolved.

A 48-YEAR-OLD WOMAN presented to Dermatology for evaluation of a 6-cm abdominal lesion that had been present for 5 weeks ­(FIGURE 1). The lesion was originally about the size of a quarter, but it started to enlarge after treatment of an asthma exacerbation with a 4-day course of prednisone. It continued to grow after another physician, likely presuming the lesion was a corticosteroid-responsive dermatosis (eg, nummular eczema, granuloma annulare, or erythema annulare centrifugum), prescribed a 2-week trial of clobetasol ointment. Physical examination revealed a mildly pruritic, 6-cm erythematous plaque with scaly, annular, concentric rings on the left lower abdomen. The patient had no travel history.

WHAT IS YOUR DIAGNOSIS?
HOW WOULD YOU TREAT THIS PATIENT?

The patient was given a diagnosis of tinea incognito, a form of tinea corporis that is exacerbated by the inappropriate use of corticosteroids in the management of a cutaneous fungal infection.¹ Furthermore, this patient’s case was consistent with tinea pseudoimbricata, a variant of tinea incognito. Tinea pseudoimbricata is characterized by striking concentric scaly rings that mimic tinea imbricata, a fungal infection caused by the dermatophyte Trichophyton concentricum, which is commonly found in tropical areas.²

A common infection is alteredby steroid use

Tinea corporis has a relatively high prevalence. Approximately 10% to 20% of the world population is affected by fungal skin infections.³ 

T rubrum is the most common cause of tinea corporis. Other causes include T tonsurans, T interdigitale, T ­violaceum, Microsporum canis, M gypseum, and M audouinii.

These steroid treatments caused the abdominal lesion to morph from the typical appearance of tinea corporis to an erythematous plaque with striking concentric scaly rings.

Tinea corporis can be acquired through direct contact with an infected person, animal, or fomite. It may also be acquired through autoinoculation from another area of the body containing a dermatophyte fungal infection. Tinea corporis lesions are usually pruritic, erythematous, annular plaques with overlying scale and central clearing.

How steroid use can change the picture. Treatment with corticosteroids is ineffective for fungal skin infections and causes immunosuppression, allowing the fungus to thrive. This patient had been treated with a topical steroid (clobetasol) for the abdominal lesion caused by tinea corporis, as well as an oral steroid (prednisone) for an asthma exacerbation. These steroid treatments caused the abdominal lesion to morph from the typical appearance of tinea corporis—classically an annular erythematous plaque with overlying scale and central clearing—to an erythematous plaque with striking concentric scaly rings.

Continue to: Clinical exam can provide clues; KOH examination can reveal the Dx

The differential diagnosis for an annular skin lesion includes not only tinea corporis, but also superficial erythema annulare centrifugum, pityriasis rosea, granuloma annulare, subacute cutaneous lupus erythematosus (SCLE), and nummular eczema.

Superficial erythema annulare centrifugum, like tinea corporis, has scale. But the location of the scale sets the 2 apart. Superficial erythema annulare centrifugum lesions have a central trailing scale, whereas tinea corporis lesions have a peripheral leading scale.⁴

Pityriasis rosea forms multiple lesions in a “Christmas tree” pattern on the trunk, sometimes beginning with a single herald patch. Our patient’s single lesion with concentric scaly rings was inconsistent with the distribution and quality of the lesions in pityriasis rosea.⁴

Granuloma annulare lesions are smooth, nonscaly plaques that are most often seen on the dorsal hands and feet. The scaly manifestation of our patient’s lesion was not consistent with this diagnosis.⁴

SCLE lesions are typically photodistributed on sun-exposed skin (eg, the neck, upper trunk, or arms), whereas our patient’s lesion involved a sun-protected site.⁴

Continue to: Nummular eczema

Nummular eczema can be differentiated from tinea corporis by potassium hydroxide (KOH) examination. Nummular eczema is characterized by a negative KOH exam and response to topical corticosteroids.⁴

Performing a KOH examination, using the skin scrapings from the active border of a plaque, is useful on any lesion with potential fungal etiology. If the cause is indeed a dermatophyte infection, segmented fungal hyphae will be seen under light microscopy (FIGURE 2).¹ If a KOH examination is not feasible, a skin scraping can be performed with a surgical scalpel blade and collected in a sterile urine cup for stain and culture at a qualified laboratory.

Topical and oral antifungal medications combat dermatophyte fungi

Treatments for cutaneous infections caused by dermatophyte fungi, such as tinea corporis, include topical and oral antifungals. The choice of agent depends on the extent of the disease.

Limited, localized disease can be treated topically with allylamines (terbinafine, naftifine) or imidazoles (clotrimazole). Other topical agents, such as butenafine, ciclopirox, and tolnaftate, also may be used.

Extensive disease, or tinea infection of vellus hairs, may require treatment with oral antifungal medications, such as the azoles (itraconazole, fluconazole), allylamines (terbinafine), or griseofulvin. Systemic therapy with oral antifungals has been associated with liver damage; therefore, oral therapy should not be used in patients with liver disease and liver enzymes should be monitored when appropriate.⁵ Nystatin is not effective in treating dermatophyte fungal infections.¹

One complication of the inappropriate use of steroids on a dermatophyte infection is an increased risk of the fungus extending from the superficial skin into the hair follicles in the dermis, resulting in a condition known as Majocchi granuloma. Follicular infection is more severe and requires oral antifungal medication, such as terbinafine, itraconazole, fluconazole, or griseofulvin.¹

Our patient was treated with terbinafine 250 mg/d for 4 weeks, due to the possibility of follicular infection. After the completion of 4 weeks of therapy, the patient’s cutaneous symptoms had resolved.

A 48-YEAR-OLD WOMAN presented to Dermatology for evaluation of a 6-cm abdominal lesion that had been present for 5 weeks ­(FIGURE 1). The lesion was originally about the size of a quarter, but it started to enlarge after treatment of an asthma exacerbation with a 4-day course of prednisone. It continued to grow after another physician, likely presuming the lesion was a corticosteroid-responsive dermatosis (eg, nummular eczema, granuloma annulare, or erythema annulare centrifugum), prescribed a 2-week trial of clobetasol ointment. Physical examination revealed a mildly pruritic, 6-cm erythematous plaque with scaly, annular, concentric rings on the left lower abdomen. The patient had no travel history.

WHAT IS YOUR DIAGNOSIS?
HOW WOULD YOU TREAT THIS PATIENT?

The patient was given a diagnosis of tinea incognito, a form of tinea corporis that is exacerbated by the inappropriate use of corticosteroids in the management of a cutaneous fungal infection.¹ Furthermore, this patient’s case was consistent with tinea pseudoimbricata, a variant of tinea incognito. Tinea pseudoimbricata is characterized by striking concentric scaly rings that mimic tinea imbricata, a fungal infection caused by the dermatophyte Trichophyton concentricum, which is commonly found in tropical areas.²

A common infection is alteredby steroid use

Tinea corporis has a relatively high prevalence. Approximately 10% to 20% of the world population is affected by fungal skin infections.³ 

T rubrum is the most common cause of tinea corporis. Other causes include T tonsurans, T interdigitale, T ­violaceum, Microsporum canis, M gypseum, and M audouinii.

These steroid treatments caused the abdominal lesion to morph from the typical appearance of tinea corporis to an erythematous plaque with striking concentric scaly rings.

Tinea corporis can be acquired through direct contact with an infected person, animal, or fomite. It may also be acquired through autoinoculation from another area of the body containing a dermatophyte fungal infection. Tinea corporis lesions are usually pruritic, erythematous, annular plaques with overlying scale and central clearing.

How steroid use can change the picture. Treatment with corticosteroids is ineffective for fungal skin infections and causes immunosuppression, allowing the fungus to thrive. This patient had been treated with a topical steroid (clobetasol) for the abdominal lesion caused by tinea corporis, as well as an oral steroid (prednisone) for an asthma exacerbation. These steroid treatments caused the abdominal lesion to morph from the typical appearance of tinea corporis—classically an annular erythematous plaque with overlying scale and central clearing—to an erythematous plaque with striking concentric scaly rings.

Continue to: Clinical exam can provide clues; KOH examination can reveal the Dx

The differential diagnosis for an annular skin lesion includes not only tinea corporis, but also superficial erythema annulare centrifugum, pityriasis rosea, granuloma annulare, subacute cutaneous lupus erythematosus (SCLE), and nummular eczema.

Superficial erythema annulare centrifugum, like tinea corporis, has scale. But the location of the scale sets the 2 apart. Superficial erythema annulare centrifugum lesions have a central trailing scale, whereas tinea corporis lesions have a peripheral leading scale.⁴

Pityriasis rosea forms multiple lesions in a “Christmas tree” pattern on the trunk, sometimes beginning with a single herald patch. Our patient’s single lesion with concentric scaly rings was inconsistent with the distribution and quality of the lesions in pityriasis rosea.⁴

Granuloma annulare lesions are smooth, nonscaly plaques that are most often seen on the dorsal hands and feet. The scaly manifestation of our patient’s lesion was not consistent with this diagnosis.⁴

SCLE lesions are typically photodistributed on sun-exposed skin (eg, the neck, upper trunk, or arms), whereas our patient’s lesion involved a sun-protected site.⁴

Continue to: Nummular eczema

Nummular eczema can be differentiated from tinea corporis by potassium hydroxide (KOH) examination. Nummular eczema is characterized by a negative KOH exam and response to topical corticosteroids.⁴

Performing a KOH examination, using the skin scrapings from the active border of a plaque, is useful on any lesion with potential fungal etiology. If the cause is indeed a dermatophyte infection, segmented fungal hyphae will be seen under light microscopy (FIGURE 2).¹ If a KOH examination is not feasible, a skin scraping can be performed with a surgical scalpel blade and collected in a sterile urine cup for stain and culture at a qualified laboratory.

Topical and oral antifungal medications combat dermatophyte fungi

Treatments for cutaneous infections caused by dermatophyte fungi, such as tinea corporis, include topical and oral antifungals. The choice of agent depends on the extent of the disease.

Limited, localized disease can be treated topically with allylamines (terbinafine, naftifine) or imidazoles (clotrimazole). Other topical agents, such as butenafine, ciclopirox, and tolnaftate, also may be used.

Extensive disease, or tinea infection of vellus hairs, may require treatment with oral antifungal medications, such as the azoles (itraconazole, fluconazole), allylamines (terbinafine), or griseofulvin. Systemic therapy with oral antifungals has been associated with liver damage; therefore, oral therapy should not be used in patients with liver disease and liver enzymes should be monitored when appropriate.⁵ Nystatin is not effective in treating dermatophyte fungal infections.¹

One complication of the inappropriate use of steroids on a dermatophyte infection is an increased risk of the fungus extending from the superficial skin into the hair follicles in the dermis, resulting in a condition known as Majocchi granuloma. Follicular infection is more severe and requires oral antifungal medication, such as terbinafine, itraconazole, fluconazole, or griseofulvin.¹

Our patient was treated with terbinafine 250 mg/d for 4 weeks, due to the possibility of follicular infection. After the completion of 4 weeks of therapy, the patient’s cutaneous symptoms had resolved.

Drawing from clinical images, researchers trained an artificial intelligence (AI) algorithm to diagnose infantile hemangiomas with an overall accuracy of 91.7%, a proof-of-concept study reported.

Early diagnosis of infantile hemangiomas “is essential, as there is a narrow window of opportunity to treat high-risk lesions,” April J. Zhang, MD, and coauthors noted in the study. “AI algorithms optimized for image classification through use of convolutional neural networks have been widely utilized to classify lesions in which images are readily standardized, such as skin cancers and onychomycosis.”

The results were published in Pediatric Dermatology.

Dr. Zhang, of the department of dermatology at the Medical College of Wisconsin, Milwaukee, and colleagues trained a convoluted neural network to diagnose infantile hemangiomas based on clinical images from pediatric dermatology patients treated at Children’s Wisconsin between 2002 and 2019.

They used Microsoft’s ResNet-50, a publicly available network architecture, to train a binary infantile hemangioma classifier to group images as infantile hemangiomas or non–infantile hemangiomas. The team randomly split data from the model into training, validation, and test groups.

The preliminary data set contained 14,811 images, about half of which were facial lesions. The training group of images achieved an accuracy of 61.5%. Next, Dr. Zhang and colleagues limited the data set to facial-only lesions and removed poor-quality images, which left 5,834 images in the final data set: 4,110 infantile hemangiomas and 1,724 non–infantile hemangiomas. This model achieved an overall accuracy of 91.7%, with a sensitivity of 93% and a specificity of 90.5%.

“Our study is the first to demonstrate the applicability of AI in the pediatric dermatology population,” the authors wrote. “With current nationwide shortages in pediatric dermatologists, AI has the potential to improve patient access and outcomes through enhanced rapid diagnostic capabilities.”

They acknowledged certain limitations of the study, including a data set with greater numbers of infantile hemangiomas, compared with non–infantile hemangiomas.

“Random oversampling of the non–infantile hemangioma data set was used to combat this but may lead to model overfitting, where a model performs well on its training data but is unable to generalize to new data,” they wrote. “As infantile hemangiomas are rarely biopsied, expert clinical diagnoses were used as the gold standard without pathologic confirmation.”

The authors reported having no financial disclosures.

Drawing from clinical images, researchers trained an artificial intelligence (AI) algorithm to diagnose infantile hemangiomas with an overall accuracy of 91.7%, a proof-of-concept study reported.

Early diagnosis of infantile hemangiomas “is essential, as there is a narrow window of opportunity to treat high-risk lesions,” April J. Zhang, MD, and coauthors noted in the study. “AI algorithms optimized for image classification through use of convolutional neural networks have been widely utilized to classify lesions in which images are readily standardized, such as skin cancers and onychomycosis.”

The results were published in Pediatric Dermatology.

Dr. Zhang, of the department of dermatology at the Medical College of Wisconsin, Milwaukee, and colleagues trained a convoluted neural network to diagnose infantile hemangiomas based on clinical images from pediatric dermatology patients treated at Children’s Wisconsin between 2002 and 2019.

They used Microsoft’s ResNet-50, a publicly available network architecture, to train a binary infantile hemangioma classifier to group images as infantile hemangiomas or non–infantile hemangiomas. The team randomly split data from the model into training, validation, and test groups.

The preliminary data set contained 14,811 images, about half of which were facial lesions. The training group of images achieved an accuracy of 61.5%. Next, Dr. Zhang and colleagues limited the data set to facial-only lesions and removed poor-quality images, which left 5,834 images in the final data set: 4,110 infantile hemangiomas and 1,724 non–infantile hemangiomas. This model achieved an overall accuracy of 91.7%, with a sensitivity of 93% and a specificity of 90.5%.

“Our study is the first to demonstrate the applicability of AI in the pediatric dermatology population,” the authors wrote. “With current nationwide shortages in pediatric dermatologists, AI has the potential to improve patient access and outcomes through enhanced rapid diagnostic capabilities.”

They acknowledged certain limitations of the study, including a data set with greater numbers of infantile hemangiomas, compared with non–infantile hemangiomas.

“Random oversampling of the non–infantile hemangioma data set was used to combat this but may lead to model overfitting, where a model performs well on its training data but is unable to generalize to new data,” they wrote. “As infantile hemangiomas are rarely biopsied, expert clinical diagnoses were used as the gold standard without pathologic confirmation.”

The authors reported having no financial disclosures.

Drawing from clinical images, researchers trained an artificial intelligence (AI) algorithm to diagnose infantile hemangiomas with an overall accuracy of 91.7%, a proof-of-concept study reported.

Early diagnosis of infantile hemangiomas “is essential, as there is a narrow window of opportunity to treat high-risk lesions,” April J. Zhang, MD, and coauthors noted in the study. “AI algorithms optimized for image classification through use of convolutional neural networks have been widely utilized to classify lesions in which images are readily standardized, such as skin cancers and onychomycosis.”

The results were published in Pediatric Dermatology.

Dr. Zhang, of the department of dermatology at the Medical College of Wisconsin, Milwaukee, and colleagues trained a convoluted neural network to diagnose infantile hemangiomas based on clinical images from pediatric dermatology patients treated at Children’s Wisconsin between 2002 and 2019.

They used Microsoft’s ResNet-50, a publicly available network architecture, to train a binary infantile hemangioma classifier to group images as infantile hemangiomas or non–infantile hemangiomas. The team randomly split data from the model into training, validation, and test groups.

The preliminary data set contained 14,811 images, about half of which were facial lesions. The training group of images achieved an accuracy of 61.5%. Next, Dr. Zhang and colleagues limited the data set to facial-only lesions and removed poor-quality images, which left 5,834 images in the final data set: 4,110 infantile hemangiomas and 1,724 non–infantile hemangiomas. This model achieved an overall accuracy of 91.7%, with a sensitivity of 93% and a specificity of 90.5%.

“Our study is the first to demonstrate the applicability of AI in the pediatric dermatology population,” the authors wrote. “With current nationwide shortages in pediatric dermatologists, AI has the potential to improve patient access and outcomes through enhanced rapid diagnostic capabilities.”

They acknowledged certain limitations of the study, including a data set with greater numbers of infantile hemangiomas, compared with non–infantile hemangiomas.

“Random oversampling of the non–infantile hemangioma data set was used to combat this but may lead to model overfitting, where a model performs well on its training data but is unable to generalize to new data,” they wrote. “As infantile hemangiomas are rarely biopsied, expert clinical diagnoses were used as the gold standard without pathologic confirmation.”

The authors reported having no financial disclosures.

A maternal or parental history of atopic dermatitis (AD) or asthma is associated with an increased risk of AD in offspring in the first 2 years of life, an analysis of a large birth cohort found.

“The prevalence of AD in children has increased dramatically in recent years, and most studies reporting the impact of parental atopic history on AD are based on older data,” wrote the study authors, led by Cathal O’Connor, MD. “Given the recent interest in early intervention to prevent AD and other allergic diseases, enhanced early identification of infants at risk of AD is increasingly important.”

The detailed analysis of AD risk associated with parental atopy in early life “may help to risk stratify infants to optimize early interventions for prevention or early treatment of AD,” they wrote.

LucaLorenzelli/Thinkstock

The study was published in Pediatric Dermatology.

For the analysis, Dr. O’Connor of the department of pediatrics and child health at University College Cork (Ireland) and colleagues conducted a secondary analysis of the Cork Babies After Scope: Evaluating the Longitudinal Impact Using Neurological and Nutritional Endpoints (BASELINE) Birth Cohort Study.

The study recruited 2,183 healthy first-born babies between August 2009 and October 2011 to examine the effects of environmental factors during pregnancy and infancy on childhood health and development. Skin barrier assessments were performed at birth, 2 months, 6 months, 12 months, and 24 months using a validated open chamber system to measure transepidermal water loss.

Parental atopy was self-reported at 2 months. Parents were asked at 2 months if the infant had an “itchy rash on the face or in the folds of the arms or legs,” as a screening question for AD. Experienced health care personnel used UK Working Party criteria to diagnose AD at 6, 12, and 24 months.

Complete data on AD status was available for 1,505 children in the cohort. Dr. O’Connor and colleagues calculated an overall AD prevalence of 18.6% at 6 months, 15.2% at 12 months, and 16.5% at 24 months.

Overall prevalence of AD was highest at 6 months. The study showed a similar or slightly higher impact of paternal atopy on offspring AD development, compared to maternal atopy.

Multivariable logistic regression analysis revealed that the odds of AD were 1.57 at 6 months and 1.66 at 12 months for maternal AD; 1.90 at 6 months and 1.85 at 24 months for paternal AD; 1.76 at 6 months and 1.75 at 12 months for maternal asthma; and 1.70 at 6 months, 1.86 at 12 months, and 1.99 at 24 months for paternal asthma.

“Parental allergic rhinitis was not associated with AD in offspring in the first 2 years, except for maternal rhinitis at 24 months [an adjusted odds ratio of 1.79],” the authors wrote. “The genetic predisposition to allergic rhinitis, given the key role of aeroallergen sensitization in its pathogenesis, may not be associated with early onset AD, but may have a greater impact in later onset or persistent AD.”

The authors acknowledged certain limitations of the study, including the fact that it was a secondary data analysis, and that parental AD, asthma, and rhinitis were self-reported, “which may reduce reliability and may contribute to the differences seen between the impact of maternal and paternal reported atopy on offspring,” they wrote. “Data on siblings were not captured, as participants in the study were first-born children. Filaggrin mutational analysis was not performed, which would have provided richer detail.”

A maternal or parental history of atopic dermatitis (AD) or asthma is associated with an increased risk of AD in offspring in the first 2 years of life, an analysis of a large birth cohort found.

“The prevalence of AD in children has increased dramatically in recent years, and most studies reporting the impact of parental atopic history on AD are based on older data,” wrote the study authors, led by Cathal O’Connor, MD. “Given the recent interest in early intervention to prevent AD and other allergic diseases, enhanced early identification of infants at risk of AD is increasingly important.”

The detailed analysis of AD risk associated with parental atopy in early life “may help to risk stratify infants to optimize early interventions for prevention or early treatment of AD,” they wrote.

LucaLorenzelli/Thinkstock

The study was published in Pediatric Dermatology.

For the analysis, Dr. O’Connor of the department of pediatrics and child health at University College Cork (Ireland) and colleagues conducted a secondary analysis of the Cork Babies After Scope: Evaluating the Longitudinal Impact Using Neurological and Nutritional Endpoints (BASELINE) Birth Cohort Study.

The study recruited 2,183 healthy first-born babies between August 2009 and October 2011 to examine the effects of environmental factors during pregnancy and infancy on childhood health and development. Skin barrier assessments were performed at birth, 2 months, 6 months, 12 months, and 24 months using a validated open chamber system to measure transepidermal water loss.

Parental atopy was self-reported at 2 months. Parents were asked at 2 months if the infant had an “itchy rash on the face or in the folds of the arms or legs,” as a screening question for AD. Experienced health care personnel used UK Working Party criteria to diagnose AD at 6, 12, and 24 months.

Complete data on AD status was available for 1,505 children in the cohort. Dr. O’Connor and colleagues calculated an overall AD prevalence of 18.6% at 6 months, 15.2% at 12 months, and 16.5% at 24 months.

Overall prevalence of AD was highest at 6 months. The study showed a similar or slightly higher impact of paternal atopy on offspring AD development, compared to maternal atopy.

Multivariable logistic regression analysis revealed that the odds of AD were 1.57 at 6 months and 1.66 at 12 months for maternal AD; 1.90 at 6 months and 1.85 at 24 months for paternal AD; 1.76 at 6 months and 1.75 at 12 months for maternal asthma; and 1.70 at 6 months, 1.86 at 12 months, and 1.99 at 24 months for paternal asthma.

“Parental allergic rhinitis was not associated with AD in offspring in the first 2 years, except for maternal rhinitis at 24 months [an adjusted odds ratio of 1.79],” the authors wrote. “The genetic predisposition to allergic rhinitis, given the key role of aeroallergen sensitization in its pathogenesis, may not be associated with early onset AD, but may have a greater impact in later onset or persistent AD.”

The authors acknowledged certain limitations of the study, including the fact that it was a secondary data analysis, and that parental AD, asthma, and rhinitis were self-reported, “which may reduce reliability and may contribute to the differences seen between the impact of maternal and paternal reported atopy on offspring,” they wrote. “Data on siblings were not captured, as participants in the study were first-born children. Filaggrin mutational analysis was not performed, which would have provided richer detail.”

A maternal or parental history of atopic dermatitis (AD) or asthma is associated with an increased risk of AD in offspring in the first 2 years of life, an analysis of a large birth cohort found.

“The prevalence of AD in children has increased dramatically in recent years, and most studies reporting the impact of parental atopic history on AD are based on older data,” wrote the study authors, led by Cathal O’Connor, MD. “Given the recent interest in early intervention to prevent AD and other allergic diseases, enhanced early identification of infants at risk of AD is increasingly important.”

The detailed analysis of AD risk associated with parental atopy in early life “may help to risk stratify infants to optimize early interventions for prevention or early treatment of AD,” they wrote.

LucaLorenzelli/Thinkstock

The study was published in Pediatric Dermatology.

For the analysis, Dr. O’Connor of the department of pediatrics and child health at University College Cork (Ireland) and colleagues conducted a secondary analysis of the Cork Babies After Scope: Evaluating the Longitudinal Impact Using Neurological and Nutritional Endpoints (BASELINE) Birth Cohort Study.

The study recruited 2,183 healthy first-born babies between August 2009 and October 2011 to examine the effects of environmental factors during pregnancy and infancy on childhood health and development. Skin barrier assessments were performed at birth, 2 months, 6 months, 12 months, and 24 months using a validated open chamber system to measure transepidermal water loss.

Parental atopy was self-reported at 2 months. Parents were asked at 2 months if the infant had an “itchy rash on the face or in the folds of the arms or legs,” as a screening question for AD. Experienced health care personnel used UK Working Party criteria to diagnose AD at 6, 12, and 24 months.

Complete data on AD status was available for 1,505 children in the cohort. Dr. O’Connor and colleagues calculated an overall AD prevalence of 18.6% at 6 months, 15.2% at 12 months, and 16.5% at 24 months.

Overall prevalence of AD was highest at 6 months. The study showed a similar or slightly higher impact of paternal atopy on offspring AD development, compared to maternal atopy.

Multivariable logistic regression analysis revealed that the odds of AD were 1.57 at 6 months and 1.66 at 12 months for maternal AD; 1.90 at 6 months and 1.85 at 24 months for paternal AD; 1.76 at 6 months and 1.75 at 12 months for maternal asthma; and 1.70 at 6 months, 1.86 at 12 months, and 1.99 at 24 months for paternal asthma.

“Parental allergic rhinitis was not associated with AD in offspring in the first 2 years, except for maternal rhinitis at 24 months [an adjusted odds ratio of 1.79],” the authors wrote. “The genetic predisposition to allergic rhinitis, given the key role of aeroallergen sensitization in its pathogenesis, may not be associated with early onset AD, but may have a greater impact in later onset or persistent AD.”

The authors acknowledged certain limitations of the study, including the fact that it was a secondary data analysis, and that parental AD, asthma, and rhinitis were self-reported, “which may reduce reliability and may contribute to the differences seen between the impact of maternal and paternal reported atopy on offspring,” they wrote. “Data on siblings were not captured, as participants in the study were first-born children. Filaggrin mutational analysis was not performed, which would have provided richer detail.”