Diagnostic Insights and Treatment Approaches for Dermatophytosis Affecting Vellus Hair.

Background: Tinea of vellus hair is a rare condition that is recalcitrant to treatment. It is typically caused by nonanthropophilic dermatophytes. Extant data on this disease remain scarce. Aims/Objectives: This study aimed to delineate the clinical features and treatment outcomes of patients with tinea of vellus hair and to compare the characteristics of patients infected by anthropophilic and nonanthropophilic species. Methods: A 10-year retrospective study was conducted at the Department of Dermatology in a tertiary hospital in Thailand. The study included all patients with tinea of glabrous skin involving vellus hair. Baseline characteristics, clinical data, and treatment outcomes were analyzed. Results: Of the 31 patients in the study, two-thirds of the patients (69%) had a history of using topical medications, mainly steroids and antifungals. The face and extremities were the most common locations for lesions with positive vellus hair. There were no significant differences in data between patients infected with anthropophilic and nonanthropophilic species. Most patients received oral antifungals (80.6%). There was no significant difference in the cure rate between patients who were administered oral antifungals and those who solely utilized topical antifungals. Kaplan-Meier analysis demonstrated the overall median duration to achieve a cure was 5 weeks. Conclusion: The diagnosis of tinea of vellus hair should be considered in cases of tinea of the glabrous skin in exposed areas, especially in patients with a history of topical treatments. Nonanthropophilic dermatophytes are the primary causative agents of tinea of vellus hair. Systemic antifungals with prolonged duration are recommended.