Bizarre annular lesion emerging as tinea incognito.

Tinea incognito has first been described in 1968. The term describes a tinea infection whose clinical morphology has been modified by the application of topical corticosteroids. The clinical manifestation can masquerade a number of other dermatoses and leads to misdiagnosis of annular eruptions. We describe a patient who showed a bizarre appearance of annular, inflammatory skin lesions at the umbilical region. Mycological culture yielded Microsporum canis.