A report describes a case of a 37-year-old healthy male who presented with a 2-month history of itchy, scaly, erythematous patches on the scalp, with broken hairs in a few regions. His medical history (including immune system/infectious diseases) was unremarkable, and he wasnt under any medication. 

Initial clinical suspicion indicated scalp psoriasis with broken hairs resulting from continuous scratching. Apart from broken hairs, erythema and white scaling, dermoscopic examination revealed findings contrasting with the clinical diagnosis, like comma hair, zig-zag hairs, corkscrew hair and Morse code hair. Fungal culture from lesional scales showed Microsporum canis, suggesting the diagnosis of tinea capitis. He took an 8-week course of oral terbinafine 250 mg/day, which resulted in complete healing.

Source: Errichetti E, Buligan C. Tinea capitis in a healthy adult: an unexpected diagnosis made on dermoscopy. Dermatol Pract Concept. 2021;11(4):e2021083.