A case of Tinea incognito diagnosed coincidentally

Tinea incognito is a dermatophytosis of atypical clinical character, usually misdiagnosed and treated with corticosteroids. A 17-year-old girl had erythematous papules and pustules on her face, diagnosed earlier as allergy and mistreated by topical corticosteroids and antihistamines. Facial lesions had only been investigated by bacteriological methods. Propionibacterium acnes was isolated on blood agar. Culture plates of the patient were inadvertently kept in the laboratory for approximately two weeks until the growth of white powdery colonies, which were identified as Trichopyton mentagrophytes complex. Epithelial scrapings were collected again and reinvestigated by mycological methods; after two weeks T. mentagrophytes complex was isolated once again on culture media. Thus, the case was diagnosed accidentally as Tinea incognito. It was realized that the patient previously was misdiagnosed and mistreated by topical steroids. J Microbiol Infect Dis 2011; 1(2): 84-86