Prevalence of undetected tinea capitis in a school survey in Spain.

From October 1994 to November 1995, a prospective study aiming to detect dermatophytes on the scalp was undertaken in 5000 unselected school children aged between 3 and 16 years (mean age 8.34 years, SD +/- 3.83). Thirty-two (0.64%) had dermatophytes in the scalp, 22. (0.44%) had tinea capitis and 10 were asymptomatic scalp carriers. It is important to point out that 33% of the patients with tinea capitis and 60% of the asymptomatic scalp carriers also had ringworm in other body sites. There was a significantly higher proportion of cases of tinea capitis (P < 0.001)(particularly due to Trichophyton tonsurans, P < 0.001) and of cases of asymptomatic scalp carriers (P < 0.05) (particularly due to Trichophyton tonsurans, P < 0.001) in the immigrant population of African origin. In all the child index cases with positive scalp cultures (tinea capitis and carriers), the household members were studied clinically and mycologically. One child had a body ringworm caused by Microsporum canis. Twelve adults had positive cultures with dermatophytosis (one tinea capitis and eleven body ringworm). Three adult patients were also carriers of dermatophytes in other body sites. Our data indicate a change in the causative agents of tinea capitis seen in Madrid over a 12-month period, with cases due to antropophilic species (T. tonsurans, T. soudanense, M. audouinii and T. violaceum) occurring in the immigrant population from Africa; as a consequence, there is an emergence of T. tonsurans in the Spanish population.