What's new in dermatology

The following represent additions to UpToDate from the past six months that were considered by the editors and authors to be of particular interest. The most recent What's New entries are at the top of each subsection.

ACNE AND ROSACEA

Risk for acne relapse after isotretinoin therapy (April 2025)

Studies assessing rates and risk factors for acne relapse after isotretinoin therapy have yielded varied results. In a retrospective study of data from over 19,000 patients treated with isotretinoin in the United States, 23 percent of patients relapsed after treatment; higher cumulative dose was associated with a reduced risk for relapse, while female sex was associated with an increased risk for relapse [1]. The daily dose did not influence the risk for relapse among patients treated with at least a conventional cumulative dose (120 mg/kg). Major limitations of the study included the use of prescription data to identify relapse and the use of population-based weight data to estimate weight-based dosing of isotretinoin. The findings support cumulative dose as a risk factor for relapse and suggest that individualizing the daily dose to support drug tolerability may be reasonable in patients who will receive at least a conventional cumulative dose of isotretinoin. (See "Oral isotretinoin therapy for acne vulgaris", section on 'Outcomes'.)

ATOPIC DERMATITIS AND OTHER DERMATITIS

Topical roflumilast for atopic dermatitis (February 2025)

Roflumilast is a selective, highly potent phosphodiesterase-4 inhibitor with anti-inflammatory properties. In two identical randomized trials including over 1300 patients with mild or moderate atopic dermatitis (AD), more patients assigned to roflumilast cream 0.15% once daily achieved the primary endpoint of Investigator Global Assessment (IGA) clear/almost clear at four weeks compared with those assigned to a vehicle control [2]. Treatment-emergent adverse effects were mild or moderate and included headache, nausea, application site pain, and nasopharyngitis. Based on these data, topical roflumilast cream 0.15% was approved by the United States Food and Drug Administration for the treatment of mild to moderate AD in adults and children ≥6 years. (See "Treatment of atopic dermatitis (eczema)", section on 'Topical roflumilast'.)

AUTOIMMUNE AND SYSTEMIC DISEASES

Dazukibart for dermatomyositis (January 2025)

Dazukibart is an investigational monoclonal antibody directed against interferon-beta, which has been implicated in the pathogenesis of dermatomyositis. In a randomized trial of 75 patients with active skin-predominant or muscle-predominant dermatomyositis, patients assigned to monthly treatments with intravenous dazukibart (either 150 or 600 mg monthly) had a greater reduction in skin disease after 12 weeks of therapy compared with those assigned to placebo [3]. In an analysis of the muscle-predominant dermatomyositis group, dazukibart at the higher dose was also associated with greater improvements in several muscle parameters, including serum creatine kinase, muscle strength, and patient global assessment, compared with patients treated with placebo. These results imply that interferon-beta blockade may be a new option for patients with dermatomyositis. (See "Initial treatment of dermatomyositis and polymyositis in adults", section on 'Rationale and selection of DMARD'.)

Spesolimab for Sweet syndrome (November 2024)

Systemic glucocorticoids are the mainstays of treatment for Sweet syndrome, an uncommon disorder characterized by neutrophilic infiltrates in the skin and systemic symptoms. The first report of treatment of Sweet syndrome with spesolimab, an interleukin-36 receptor monoclonal antibody, describes rapid clinical improvement in a patient with Sweet syndrome who was refractory to systemic glucocorticoids [4]. Although this report suggests spesolimab is a potentially useful treatment for refractory Sweet syndrome, efficacy and safety for this indication have not been confirmed. (See "Sweet syndrome (acute febrile neutrophilic dermatosis): Management and prognosis", section on 'Recalcitrant disease'.)

HAIR AND SCALP DISEASE

Epistatic interaction between ERAP1 and MHC class I alleles in frontal fibrosing alopecia (March 2025)

The pathogenesis of frontal fibrosing alopecia (FFA), a form of cicatricial (scarring) alopecia, is not fully understood. A meta-analysis of four genome-wide association studies of female patients with FFA supported an association between FFA and select major histocompatibility complex (MHC) class I alleles and identified a new association with endoplasmic reticulum aminopeptidase 1 (ERAP1), which encodes a protein involved in antigen presentation to MHC class I molecules [5]. Genetic variation at the ERAP1 locus augmented FFA risk only among individuals carrying one or more MHC class I risk alleles. The findings suggest that epistatic interaction between MHC class I risk alleles and ERAP1 may contribute to FFA. (See "Frontal fibrosing alopecia: Pathogenesis, clinical manifestations, and diagnosis", section on 'Pathogenesis'.)

Oral metformin for central centrifugal cicatricial alopecia (March 2025)

Central centrifugal cicatricial alopecia (CCCA) is an inflammatory scalp disorder resulting in follicular destruction, scalp fibrosis, and permanent hair loss. In a case series of 12 patients given adjunctive oral metformin (a drug with antifibrotic properties) for CCCA, eight had symptom improvement and six had partial hair regrowth [6]. Transcriptional analysis of scalp biopsies demonstrated downregulation of fibrosis-related pathways and upregulation of pathways related to hair regrowth. These findings do not confirm efficacy of metformin but add to case reports of hair regrowth in CCCA with topical metformin and support further evaluation of metformin therapy. (See "Central centrifugal cicatricial alopecia", section on 'Other therapies'.)

Oral brepocitinib for cicatricial alopecia (March 2025)

Cicatricial forms of alopecia result in permanent hair loss and are often challenging to treat. In a trial in which patients with central centrifugal cicatricial alopecia, lichen planopilaris, or frontal fibrosing alopecia were randomly assigned to the investigational tyrosine kinase 2 (TYK2) and Janus kinase 1 (JAK1) inhibitor brepocitinib (n = 37) or placebo (n = 12), those receiving brepocitinib had reduced inflammatory biomarkers in lesional skin as well as clinical improvement compared with placebo [7]. The most common adverse effects with brepocitinib were acne, COVID-19 infection, anemia, and elevated serum creatinine levels; two patients stopped the drug due to adverse effects (anemia and pneumonia with gastroenteritis). Although further study is necessary to confirm the efficacy and safety of brepocitinib, these findings suggest benefit for cicatricial alopecia. (See "Central centrifugal cicatricial alopecia", section on 'Other therapies'.)

INFECTIONS AND INFESTATIONS

New reports of Trichophyton mentagrophytes genotype VII infection in the United States (November 2024)

Trichophyton mentagrophytes genotype VII infection, an emerging dermatophyte infection that can spread through sexual contact, has been primarily documented in reports from Europe. A new report adds four patients to a single preceding report of this infection in the United States, including three patients with no recent international travel [8]. Clinical findings may include pruritic, scaly, annular patches or plaques, or inflamed papules in sites such as the trunk, groin, genitals, or face. Definitive diagnosis requires DNA sequencing; extended courses of oral antifungal therapy may be necessary for resolution. This report supports increased awareness of T. mentagrophytes genotype VII infection in the United States. (See "Dermatophyte (tinea) infections", section on 'Tinea genitalis'.)

PEDIATRIC DERMATOLOGY

Long-term safety of oral propranolol for infantile hemangiomas (December 2024)

Oral propranolol is the standard-of-care treatment for infantile hemangiomas (IH) at risk of impairing function or causing permanent disfigurement. Several studies have addressed the concerns about potential long-term adverse effects of propranolol in children. The largest study using data from a database of electronic medical records from multiple health institutions did not find any statistically significant differences in the risk of growth impairment, sleep disorders, learning disabilities, and diabetes mellitus between a cohort of over 1000 children aged 10 to 17 years who had received propranolol for IH in the first year of life and an age-, sex-, and ethnicity-matched cohort of children who had never received propranolol [9]. These findings support propranolol as a safe treatment for IH in infants who do not have contraindications to its use. (See "Infantile hemangiomas: Management", section on 'Long-term safety'.)

PSORIASIS AND OTHER PAPULOSQUAMOUS DISORDERS

Axial spondyloarthritis in patients with psoriasis, uveitis, or inflammatory bowel disease (January 2025)

Axial spondylarthritis (axSpA) often goes unrecognized in patients with chronic back pain who also have psoriasis, acute anterior uveitis, or inflammatory bowel disease. In two prospective cohort studies of over 350 such patients with undiagnosed chronic back pain, axSpA was present in approximately 25 percent of patients with psoriasis or inflammatory bowel disease and 60 percent of patients with acute anterior uveitis [10]. However, musculoskeletal symptoms, response to nonsteroidal anti-inflammatory drugs, and family history (which are commonly used to identify axSpA) did not help discriminate axSpA from other causes of chronic back pain. This study implies that axSpA is common in patients with psoriasis, acute anterior uveitis, or inflammatory bowel disease, but may be challenging for a nonexpert to distinguish from other causes of chronic back pain. (See "Diagnosis and differential diagnosis of axial spondyloarthritis (ankylosing spondylitis and nonradiographic axial spondyloarthritis) in adults", section on 'History'.)

Home-based versus office-based narrowband UVB phototherapy for psoriasis (November 2024)

Narrowband UVB phototherapy is an effective treatment for psoriasis, but its use is often limited by burdens, such as multiple clinic visits per week for in-office treatment. In a randomized trial of nearly 800 adults and adolescents with plaque psoriasis or guttate psoriasis (the LITE trial), at 12 weeks, patients treated with home phototherapy were more likely to have clear or almost clear skin (33 versus 26 percent) and report a nonexistent or small negative effect on quality of life (52 versus 34 percent) than patients treated with office phototherapy [11]. Patients receiving home phototherapy also had higher treatment adherence. Both treatments were well tolerated, but sunburn was slightly more common in the home phototherapy group. Some limitations of the trial included variation in the treatment regimens for office phototherapy, missing data, and limited cost difference analysis. The findings provide further support for home phototherapy as an effective and appropriate modality for patients who prefer home-based narrowband UVB treatment. (See "Chronic plaque psoriasis in adults: Treatment of disease requiring phototherapy or systemic therapy", section on 'Administration'.)

URTICARIA AND ANGIOEDEMA

Antileukotriene drugs minimally helpful in chronic spontaneous urticaria (November 2024)

The benefit of adding a leukotriene receptor antagonist (LTRA) such as montelukast for patients with chronic spontaneous urticaria that is not controlled with antihistamines alone has not been clear. In a new meta-analysis of 34 randomized trials including over 3000 children and adults, the efficacy of a LTRA added to a nonsedating antihistamine at standard dose was compared with antihistamine alone [12]. The addition of LTRAs provided some benefit, but the degree of improvement on the Urticaria Activity Score was just 5 points, which was less than half of the minimally important difference of 11 points for the symptom scale used. Based upon these findings, we do not advocate for the use of LTRAs in the routine management of chronic spontaneous urticaria. (See "Chronic spontaneous urticaria: Standard management and patient education", section on 'Leukotriene modifiers'.)

OTHER DERMATOLOGY

JAK inhibitors for Stevens-Johnson syndrome/toxic epidermal necrolysis (December 2024)

Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a severe drug-induced mucocutaneous reaction for which there is no established pharmacologic treatment other than supportive care. Based on in vitro and preclinical data showing marked upregulation of the JAK/STAT pathway in both keratinocytes and immune cells in SJS/TEN, seven patients were treated with an oral JAK inhibitor (abrocitinib or tofacitinib) for two weeks [13]. All patients also received high-dose intravenous glucocorticoids. In all patients, JAK inhibition was associated with rapid clinical improvement and re-epithelialization without treatment-related adverse events. These findings suggest a beneficial effect of JAK inhibitors for SJS/TEN, but further studies are needed to confirm their efficacy and optimal use. (See "Stevens-Johnson syndrome and toxic epidermal necrolysis: Management, prognosis, and long-term sequelae", section on 'JAK inhibitors'.)

Hidradenitis suppurativa and adverse maternal and neonatal outcomes (November 2024)

Although hidradenitis suppurativa (HS) is a relatively common disorder, studies assessing pregnancy and neonatal outcomes for patients with HS are limited. In a retrospective study of short- and long-term hospitalization data from mothers and neonates from over 1 million hospital births in Canada, maternal HS was associated with increased risk for adverse maternal pregnancy outcomes and pregnancy complications (eg, hypertensive disorders of pregnancy, gestational diabetes, severe maternal morbidity, preterm birth, and congenital anomalies) [14]. Both mothers with HS and their neonates also had an increased long-term risk for rehospitalization. These findings provide further support for a link between HS and adverse pregnancy outcomes and provide new insight into long-term adverse health events in the children of mothers with HS. (See "Hidradenitis suppurativa: Pathogenesis, clinical features, and diagnosis", section on 'Associated disorders and syndromes'.)