A case of tinea incognito.

Tinea incognito is a dermatophyte infection of the skin that presents atypically because it has previously been treated with imunnosuppresive medication. Herein we present a case of a middle-aged man who was initially clinically diagnosed to have plaque-type psoriasis on his arms. Over the course of two months of topical hydrocortisone and calciptriol treatment as well as phototherapy, the rash worsened. At the time of presentation to hospital the patient had a pruritic, widespread, sloughing, erythematous rash with areas of eschar. A punch biopsy skin confirmed dermatophyte fungal infection of the skin. Fungal culture was positive for Trichophyton Rubrum and the eruption resolved with systemic anti-fungal therapy. Patient specific risk factors for atypical presentation included poor hygiene and hepatatic disease.