Trichoscopic features of tinea capitis among primary school children in north central Nigeria

The myriad of coexisting risk factors for tinea capitis (TC) in parts of Africa makes it common among schoolchildren from this region. Diagnosis ideally involves microscopy and culture of scalp scrapings, which is not always feasible in resource-poor settings. Small-scale reports have identified trichoscopy (dermoscopy of hair and surrounding skin) as a cheap, quick, and simple tool for evaluating TC. We sought to describe the trichoscopic features of TC among Nigerian children.

A total of 204 children with clinically diagnosed TC had trichoscopy of their scalp lesions and culture of scalp scrapings. Trichoscopic features and culture results were noted.

Perifollicular scaling (78.4%), interfollicular scaling (69.1%), and black dots (44.1%) were the commonest trichoscopic features. Others include regrowing hairs (18.6%), comma hairs (14.7%), broken hairs (13.2%), corkscrew hairs (3.4%), zigzag hairs (2.5%), and peripilar casts (2.0%). All children with comma, corkscrew, and zigzag hairs, as well as most with black dots (88.9%), broken hairs (88.9%), and regrowing hairs (77.5%) had positive cultures, irrespective of the isolated dermatophyte. Comma hairs were specific for Tinea infection with positive culture of dermatophytes. The presence of black dots in combination with individual features like broken hairs, regrowing hairs, perifollicular scaling, or interfollicular scaling also had a high specificity for positive cultures.

In the management of children with TC, trichoscopy is useful as a diagnostic tool, especially where access to laboratory evaluation is either not instant or unavailable.