Tinea corporis caused by an unusual strain of Microsporum audouinii that perforates hair in vitro.

We report on a dermatophyte infection acquired by a young woman from Germany who had worked in Ghana. The strain isolated from her skin lesions showed morphological and physiological features compatible with Microsporum audouinii but a clearly positive hair perforation test made its definite identification by conventional methods equivocal. A genetic analysis finally unambiguously revealed Microsporum audouinii. This is the first observation of a Microsporum audouinii strain with a positive hair perforation test. The ability to perforate hair may be related to attributes favouring an inflammatory host response.