Psoriasis-like tinea incognita: a case report and literature review

Abstract

Tinea incognita is an atypical presentation of fungal infection of the skin, the clinical presentation of which has been modified by misuse of topical corticosteroids or calcineurin inhibitors. Such dermatophyte infections often have an atypical clinical presentation and are difficult to diagnose, but with the rise of immunosuppressive drugs and self-prescribed topical therapies, they are becoming increasingly prevalent. Here we report the case of a 68-year-old male patient with a history of psoriasis, presenting with erythematous scaly lesions, that did not respond to conventional treatment for psoriasis, as would be expected. A diagnosis of tinea incognita was made with histopathological examination with periodic acid-Schiff stain of a skin biopsy sample. This case highlights the fact that dermatophyte infections are widespread but sometimes neglected and can occur concomitantly with other dermatoses.