LS4 TINEA CAPITIS
Hay RJ
Faculty of Medicine and Health Sciences, Queen’s University Belfast, Ireland

Tinea capitis is a childhood scalp infection caused by dermatophyte fungi. It is usually spread either from animal (zoophilic) or human (anthropophilic) sources. Until recently the commonest pathogen in Europe was Microsporum canis (from cats of dogs) but recently there has been a rapid increase of anthropophilic infections generally caused by Trichophyton tonsurans in inner city areas of the parts of the USA and Europe spreading to South America, the Caribbean and Africa. By contrast there has been spread of M. canis infections in North and Central Europe. The clinical manifestations of hair loss and scaling may be muted with T. tonsurans infections where symptoms are often minimal, particularly in African Caribbean children. Indeed in a significant proportion of cases without apparent clinical signs careful examination of the scalp reveals isolated and infected hair shafts. There is no evidence, following molecular typing, that new strains have been introduced and are responsible for this new epidemic. Infected cases appear to retain the same strain type throughout infection. Carriage, as well as spread in the home or classroom environment, is a potential source of continued and endemic infection; significant numbers of fungal spores are shed into the environment in the vicinity of an infected child. They may also be carried for limited periods in the scalps of adults and children in the vicinity. Adults in the same household are often infected, usually with tinea corporis. There is often evidence of delayed onset of effective TH2 immune responses in infected children. Treatment of the infection depends on detection of infected cases using techniques such as scalp brush cultures. Therapy is with oral antifungal drugs such as terbinafine, itraconazole or griseofulvin. The latter is no longer available in the many countries as a paediatric formulation. Terbinafine is more effective than griseofulvin in Trichophyton infections whereas terbinafine is not as effective in Microsporum infections unless the dose is doubled. Itraconazole can be used as a pulsed dose regimen. Carriage is usually treated with topical therapy such as ketoconazole shampoo or selenium sulphide. However there is evidence that some of those recorded as carriers have limited infections and do not respond to topical treatment.