Tinea incognito due to Microsporum gypseum in three children.

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 steroids, sometimes prescribed as a result of incorrect diagnosis. The cases reported in the literature have different clinical presentations and have generally been in adults. We report three children with tinea incognito in whom the lesions were psoriasis-like, eczema-like, and lichenoid, respectively. Diagnosis was confirmed by mycologic examination, which led to the identification of Microsporum gypseum, a geophilic dermatophyte which is an infrequent agent of mycotic infection in humans.