A Case of Tinea Incognito Presented like Furunculosis / 대한의진균학회지

ABSTRACT

Tinea incognito is a dermatophytosis of atypical clinical character due to the absence of classic features of ringworm. It is caused by prolonged use of topical or systemic corticosteroids, sometimes prescribed as a result of incorrect diagnosis. We report a case of tinea incognito presented like furunculosis on the chin. The patient had been treated with topical and oral corticosteroid under the impression of atopic dermatitis for 3 years for the eczematous lesion on the face and trunk. Mycologic studies including KOH mount and fungus culture were positive for hyphae and colonies of Trichophyton rubrum. Skin biopsy showed fungal hyphae in follicular keratinous plug and diffuse dermal and perifollicular inflammation. The lesion was treated with terbinafine systemically and cured 3 months later.