Faculty Bibliography

Granuloma annulare (GA) is an inflammatory skin disease typically characterized by an erythematous eruption consisting of papules and annular plaques. GA can have a severe impact on quality of life, especially when widespread. GA can be difficult to treat and often recurs after treatment is stopped; there remain no FDA-approved therapies. In recent years, there has been significant progress in understanding the epidemiology, disease associations, and molecular pathogenesis of GA. Patients with GA are more likely to have hyperlipidemia, diabetes mellitus, and autoimmune diseases including thyroiditis, rheumatoid arthritis, and systemic lupus erythematosus. These associations further underscore the importance of recognizing GA and evaluating for comorbid disease. Accurate diagnosis of GA requires distinguishing it from its clinical and histologic mimics, some of which share annular morphology or granulomatous inflammation. Molecular work has suggested a T-cell mediated pathogenesis and identified key cytokines and other signals that drive macrophage accumulation and activation in tissue. Emerging therapies that block these cytokine signals are showing promise in the clinic. In this article, we provide an updated overview of the epidemiology, disease associations, clinical and histopathologic characteristics, molecular pathogenesis, and treatment of GA.

Tinea corporis and tinea cruris are common dermatophyte infections of increasing public health concern, yet national U.S. data are limited. We estimated incidence, risk factors, diagnostic and treatment practices among a large Medicaid-insured outpatient cohort. Among ∼6 800 000 enrollees, 54 108 were diagnosed with tinea corporis (79.1/10 000 person-years) and 8 386 with tinea cruris (12.2/10 000 person-years). Tinea corporis primarily affected young children and Black patients, while tinea cruris was prevalent among middle-aged men. Overall, less than 10% received diagnostic testing, and 7-10% were treated with combination antifungal-corticosteroid products, highlighting the opportunities to increase testing and promote judicious antifungal use amid emerging resistance.

Sporotrichosis is an implantation mycosis caused by Sporothrix species. The global burden of disease is largely unknown, as routine surveillance is not conducted in most countries. The increasing disease burden paired with emerging zoonotic transmission highlight the growing public health significance of sporotrichosis. In this article, we describe the epidemiology and outline an approach to the diagnosis and treatment of sporotrichosis.

Tinea infections (often called ringworm) are caused by dermatophyte fungi and classified by the body site involved. Tinea corporis and tinea capitis are most common in prepubertal children, and tinea cruris, tinea pedis, and tinea unguium (most common type of onychomycosis) are more likely in adolescents and adults. Clinical diagnosis without testing may be unreliable because other conditions can resemble tinea infections (eg, tinea corporis can be confused with eczema, and onychomycosis with dystrophic toenails from repeated low-level trauma or psoriasis). Tinea corporis, tinea cruris, and tinea pedis generally respond to inexpensive topical antifungal agents, but oral antifungal agents may be indicated for patients with extensive disease, lack of response to topical treatment, immunocompromise, or hair follicle involvement (eg, tinea capitis). Oral terbinafine is considered first-line therapy for tinea capitis and onychomycosis because it is well tolerated, effective, and inexpensive. Emerging tinea infections may be more severe than classic tinea infections and generally do not improve with first-line topical or oral antifungals. These infections may require prolonged oral antifungal therapy and specialized diagnostic testing. Antifungal stewardship, including avoiding the use of combination antifungal-corticosteroids, should be emphasized to optimize outcomes and help prevent resistance.

Cutaneous lupus erythematosus (CLE) is an autoimmune disease with diverse clinical manifestations, including patchy hair loss resembling alopecia areata (AA). This report describes two cases of CLE presenting as AA mimickers, emphasizing the need to consider CLE in differential diagnosis for patchy hair loss. Early and accurate diagnosis is crucial for effective management and preventing scarring alopecia. J Drugs Dermatol. 2025;24(3):324-326. doi:10.36849/JDD.7793R1.