Dermoscopic Features seen in Tinea Capitis, Tinea Corporis and Tinea Cruris

Superficial fungal infections (SFIs) are infections affecting the keratinized layer of the skin, nail and hair that are mainly caused by dermatophytes. Although diagnosis is routinely done clinically and confirmed by direct potassium hydroxide (KOH) microscopy, fungal culture remains the gold standard for diagnosis and speciation of aetiological agents. Dermoscopy is a recent non-invasive diagnostic tool used to identify features of tinea infections. This study is aimed primarily at identifying specific dermoscopic features seen in tinea capitis, tinea corporis and tinea cruris, and secondarily, to compare dermoscopic features between the three diseases.

This is a cross sectional study of 160 patients with suspected superficial fungal infection using a handheld dermoscope. Skin scrapping with 20% KOH microscopy was done, fungal culture was grown on Sabouraud dextrose agar (SDA) and species identified further.

There were 20 different dermoscopic features observed in tinea capitis, thirteen in tinea corporis, and twelve in tinea cruris. The commonest dermoscopic feature in tinea capitis was corkscrew hairs, observed in 49 of the 110 patients. This was followed by black dots and comma hairs. There were similar dermoscopic features in tinea corporis and tinea cruris with interrupted hairs and white hairs being the most common features seen respectively. The presence of scales was the dominant feature observed across these three tinea infections.

Dermoscopy is being used constantly in dermatology practice to improve clinical diagnosis of skin disorders. It has been shown to improve the clinical diagnosis of tinea capitis. We have described the dermoscopic features of tinea corporis and cruris and compared them with that of tinea capitis.