Trichoscopic signs of tinea capitis: a guide for selection of appropriate antifungal.

Background: Tinea capitis is the most common pediatric dermatophyte infection. Optimal treatment regimen differs according to the type of the dermatophyte involved.
Objectives: The aim of this work was to study the trichoscopic signs in relation to isolated organism in a sample of Egyptian patients with tinea capitis and the possibility of using them as a guide for selection of appropriate antifungal.
Methods: This study was carried out on 60 subjects with tinea capitis. Patients were mycologically examined, both direct microscopy with KOH preparation and culture of the scraped hair materials on Sabouraud dextrose agar. Culture mounts were used for identification of the organism. Trichoscopic examination of all patients was performed using the Dermlite DLIII dermoscope.
Results: There was significant higher prevalence of both comma and corkscrew hair in endothrix infection and T. violaceum-infected cases. On the other hand, there was significant higher prevalence of zigzag, barcode hairs, and white sheaths in ectothrix infection and M. canis-infected cases.
Conclusion: While some trichoscopic findings are nonspecific, others were found to be more specific. Finding zigzag hairs and barcode hairs points to ectothrix infection (M. canis), and it is recommended to start treatment with griseofulvin. On the other hand, finding comma hairs and corkscrew hairs without zigzag hairs and barcode hairs points to endothrix infection (T. violaceum), and it is recommended to start treatment with terbinafine in the usual dose.
(© 2020 the International Society of Dermatology.)