Prevalence of Undetected Tinea Capitis in Household Members of Children with Disease

The epidemiology of tinea capitis has changed over the past 40 years. The major organism responsible for tinea capitis today is Trichophyton tonsurans. This dermatophyte accounts for more than 90% of ringworm infections of the scalp in the United States and replaces Microsporum audouinii and to a lesser extent Microsporum canis, which were associated with the ringworm epidemics of the 1940s.1-4 Trichophyton tonsurans is an anthropophilic organism producing endothrix invasion of the hair shaft that does not fluoresce on Wood's light examination.5 Tinea capitis is epidemic in black school-age children, but only rarely in whites. The reason for this racial predilection is not known.1