Treatment of tinea capitis - a critical appraisal

Griseofulvin has been introduced in 1958, ever since it remained the gold standard for the treatment of tinea capitis in the United States. Despite the availability of new antifungals like terbinafine, itraconazole and fluconazole -with few exceptions not licensed for their use in children - duration of tinea capitis treatment could not be shortened. The reasons therefore are the anatomic structure of the hair follicle, the dormant sebum-production before onset of puberty, and the way of action of the new antifungals. Although data concerning the pharmacokinetics of allylamines and triazoles in childhood-populations are lacking, some experience confirms a correlation of the way of action of modern antifungals and the causative pathogen. In children the treatment of Microsporum infections of the scalp is crucial. That may be explained by the unique pharmacokinetic features of the substance of terbinafine: Terbinafine neither can be excreted by sweat nor by sebum before onset of puberty. Terbinafine is incorporated in the keratin of mature terminal hair in the anagen phase. In children it will not be built in the hair shaft and therefore it will not reach the surface of the scalp where the sheets of arthro-conidia in microsporosis are located. This peculiar fact was not yet considered in clinical studies.