Prevalence of undetected tinea capitis in a prospective school survey in Madrid: emergence of new causative fungi.

From October 1994 to December 1996, a prospective study was undertaken in 10,000 unselected school children in Madrid, aged between 2 and 16 years (mean +/- SD 8.5 +/- 3.6 years). Fifty-two (0.52%) (including 13 immigrants from Africa) had dermatophytes in the scalp: 33 (0.33%) (including 10 immigrants from Africa) had tinea capitis and 19 were scalp carriers. Almost half of the symptomatic cases were caused by Trichophyton tonsurans (12 of 33 cases) and Microsporum canis (16 of 33 cases). T. tonsurans (13 of 19 cases) was the predominant species in the scalp carriers. Twenty-four per cent of the subjects with tinea capitis and 42% of the asymptomatic scalp carriers also had ringworm in other body sites. There was a significantly higher occurrence of tinea capitis (P < 0.001) (particularly due to T. tonsurans: P < 0.001) and of asymptomatic scalp carriers (P < 0.05) (particularly due to anthropophilic species: P < 0.01) in the immigrant population from Africa.