Abstract
A three-year-old girl and her sixty-two-year-old grandmother, living in Niigata Prefecture of Japan, had a black dot ringworm form of tinea capitis about one year ago. Recently a five-month-old boy, a cousin of the girl, also contracted tinea corporis. In the cultures of affected hairs and scales, violetcolored fungi grew on the Sabouraud's media, and subcultured colonies of these fungi showed a white suede-like surface. These fungi were identified to be Trichophyton tonsurans from the above mentioned and following characteristics: no hair perforation, positive urease test, no pigment production on the cornmeal and oatmeal agar and the ability to produce abundant microconidia, intercalary chlamydospores and rare macroconidia. These are the first reports of T. tonsurans infection observed in Niigata Prefecture. In addition, the grandmother and mother of the boy had previous histories of tinea corporis, and violet-colored fungi were isolated from the lesions at that time. Since further identification of these fungi was not performed, it is not clear whether they were T. tonsurans or not. T. tonsurans has been isolated almost exclusively in Kyushu Island and only a few cases of tinea capitis due to T. tonsurans have been reported in other areas of Japan. Although it was found that, a family originating from Kyushu Island had been living until about two years previously in the neighborhood of the girl in the present case, we were not able to clarify the invading course of the causative fungi of the current cases.
