Clinical study of 57 cases of infection with Trichophyton tonsurans examined at a dermatology clinic in Saga Prefecture, Japan]

This paper is a clinical study of 57 cases of infection with Trichophyton tonsurans (T. tonsurans) examined in our clinic between January 2004 and July 2006. The patients were 31 high school students, 19 junior high school students, 2 primary school students, 1 kindergartener, and 4 sports instructors. The male:female ratio was 51:6. Most patients were male Judo practitioners. Patients were clinically categorized as follows: 13 cases of tinea capitis {10 containing black dot ringworms (BDR), 2 scaled, and 1 with inflammation}, 41 cases of tinea corporis, 1 case of tinea manum, and 7 carriers. Five patients displayed both tinea capitis and tinea corporis. Among tinea corporis patients, 21 displayed annular erythemas, whereas 19 displayed small circular eythemas characterized by a lightly inflamed non-typical rush. In 3 tinea corporis cases, we sampled T. tonsurans from hair grown inside the skin rash. Eleven of the tinea corporis patients displayed multiple lesions. Compared to patients with singular lesions, these 11 cases had a larger degree of comorbidity with BDR or HB positivity. A 6-8 week treatment with griseofulvin was efficient in 90% of the tinea capitis cases. Tinea corporis patients were healed following a 4-9 week treatment with topical antifungals and griseofulvin. When examining T. tonsurans infections, patients with BDR or lightly inflamed tinea corporis as well as asymptomatic carriers can be easily overlooked or misdiagnosed. Therefore, we suggest that mycological examination, including careful observation of the rash and KOH mount, is essential in these cases.