Tinea capitis is a disease caused by superficial fungal infection of the skin of the scalp, eyebrows, and eyelashes, with a propensity for attacking hair shafts and follicles. The disease is considered to be a form of superficial mycosis or dermatophytosis. Several synonyms are used, including ringworm of the scalp and tinea tonsurans. In the United States and other regions of the world, the incidence of tinea capitis is increasing.
Hair can be infected with Trichophyton and Microsporum fungi.
Types of tinea capitis infections
Tinea capitis is classified according to how the fungus invades the hair shaft.
Ectothrix hair invasion is due to infection with M. canis, M. audouinii, M. distortum, M. ferrugineum, M. gypseum, M. nanum, and T. verrucosum. The fungal branches (hyphae) and spores (arthroconidia) cover the outside of the hair.
Endothrix invasion results from infection with T. tonsurans, T. violaceum and T. soudanense. The hair shaft is filled with fungal branches (hyphae) and spores (arthroconidia).
Favus is caused by T. schoenleinii infection, which results in a honeycomb destruction of the hair shaft.