Dermoscopy: an auxiliary tool in distinction between the main causative agents of tinea capitis

Abstract

Background Tinea capitis (TC) is the fungal infection of scalp skin and hairs by dermatophyte fungi. In Egypt, Trichophyton violaceum and Microsporum canis were the most commonly detected dermatophytes in TC. Etiological diagnosis is confirmed by fungal culture. However, lack of availability and delayed results of this confirmatory procedure may postpone the treatment increasing the chance of contagion. Dermoscopic examination is a fast and inexpensive technique that is recommended as a complementary tool to diagnose TC. The aim of our study is to spot dermoscopic features that may help dermatologists to differentiate between TC caused by T. violaceum and TC caused by M. canis. Patients and methods Our study describes 87 child patients clinically diagnosed with TC, comprising 61 patients with TC by M. canis and 26 patients by T. violaceum, who were mycologically confirmed by direct KOH test and fungal growth on Sabouraud's agar media. Dermoscopic examination was performed by DermLite II PRO HR. Results The observed dermoscopic features among 61 patients infected with M. canis were comma hairs in 48 (78.7%) cases, broken hairs in 52 (85.2%) cases, diffuse scaling in 48 (78.7%) cases, corkscrew hairs in 38 (62.3%) cases, and proximal sheath in 33 (54.1%) cases. Dermoscopic features among 26 patients infected with T. violaceum were comma hairs in 24 (92.3%) cases, broken hairs in 18 (69.2%) cases, diffuse scaling in eight (30.8%) cases, corkscrew hairs in 19 (73.1%) cases, and proximal sheath in six (23.1%) cases. Conclusion Dermoscopy can be used as an auxiliary tool in predicting the possible causative agent in suspected TC cases.