Whereas all three genera attack the skin, Microsporum does not infect nails and Epidermophyton does not infect hair. Tinea capitis in general is predominantly an infection of children, although adult cases are occasionally seen. Tinea capitis may also be seen in adults with AIDS.
The clinical appearance of tinea capitis is most variable,
depending on the type of hair invasion, the level of host resistance and the degree of inflammatory host response. The appearance therefore may vary from a few dull grey, broken-off hairs with a little scaling, detectable only on careful inspection, to a severe, painful, inflammatory mass covering most of the scalp. Itching is variable. In all types, the cardinal features are partial hair loss with inflammation of some degree.
It should be noted that the phenomenon of producing a characteristic fluorescence by hair infected by certain dermatophytes on Wood's light examination has been attributed to some substance produced by the interaction of the fungus and the growing hair. Its chemical nature has not been defined, and the suggestion that it may be a pteridine has been challenged.
Tinea capitis is treated systemically; additional topical application of an antifungal may reduce transmission.
A topical antifungal can also be used to treat asymptomatic carriers of tinea capitis. There is evidence that ketoconazole shampoo may reduce the incidence of positive cultures.
Griseofulvin is used for tinea capitis in children and adults, it is effective against infections caused by both Trichophyton species and Microsporum spp. Terbinafine is an alternative for certain infections such as those caused by Trichophyton species. The role of terbinafine in the management of Microsporum infections is uncertain. (Griseofulvin for at least 6 weeks - Terbinafine for at least 4 weeks). Fluconazole or itraconazole are alternatives in the treatment of tinea capitis. The appropriate length of treatment with either itraconazole or fluconazole is not established.
In severely inflammatory forms, there has been some argument in favour of using systemic steroids to inhibit the inflammatory response. While this view has its supporters, all cases should generally be reviewed early after the institution of antifungal therapy, and only systemic steroids are used in severe cases with widespread ide reactions.
When treatment failure occurs certain points should be checked e.g. diagnosis, interactions, HIV, co-pathogens, antifungalresistance and reinfection.
In small-spored ectothrix infections (scaly tinea capitis),
griseofulvin for at least 6 weeks is usually adequate.
This page was last updated in February 2014.