Evaluation of dermatoscopic findings of alopecia areata and tinea capitis in pediatric patients.

Abstract

Pediatric patients often reveal localized alopecic foci on the scalp. The essential point upon approaching a child with localized alopecia is distinguishing the two most common causes, alopecia areata and tinea capitis, as their treatments are entirely different. Although potassium hydroxide examination is the preferred method for their clear distinction, dermatoscopy is also emerging as a rapid diagnostic tool. This study aimed to assess and compare the dermatoscopic findings of alopecia areata and tinea capitis. Enrolled in this study were 34 children with tinea capitis and 21 children with alopecia areata admitted to a single-center outpatient clinic between 2017 and 2021. The authors confirmed all children's diagnoses by an integrative evaluation of clinical features, potassium hydroxide examination results, and treatment response patterns. Clinical features and the variables of interest (dermatoscopic findings) were investigated through the medical records and the baseline dermatoscopic images. The most common dermatoscopic finding within the tinea capitis cohort was comma hairs, detected in 33 (97.1%) of the patients. Other findings of the tinea capitis group included squamation (n=31, 91.2%), broken and dystrophic hairs (n=30, 88.2%), corkscrew hairs (n=24, 70.6%), zigzag hairs (n=18, 52.9%), and pigtail hairs (n=9, 26.5%). The most common dermatoscopic finding within the alopecia areata cohort was exclamation mark hairs (n=13, 61.9%), that was followed by black dots (n=9, 42.9%), yellow dots (n=8, 38.1%), vellus hairs (n=6, 28.6%), and broken and dystrophic hairs (n=5, 23.8%). Among the detailed evaluation of dermatoscopic findings of tinea capitis and alopecia areata patients, the only overlapping feature was dystrophic and broken hairs that could be present in both diseases; but were more common within the TC group than within the AA group (88.2% vs. 23.8%).