Tinea capitis asymptomatic carriers: what is the evidence behind treatment?

Tinea capitis is a fungal infection mostly affecting children. Epidemiology is changing over time due to migration, and it has been estimated that up to 40% of children from certain developing countries are affected. The mechanism of transmission is still unclear although asymptomatic carriage seems to have an influence in establishing persistent reservoirs that can cause or fuel epidemics. Screening and prophylactic treatment of close contacts of tinea capitis patients are therefore recommended by several international guidelines, but vaguely and not consistent. The treatments involved can be expensive, hard to integrate in everyday life, have well-known side effects and some are not approved for the treatment of children. The aim of this review was to clarify the evidence behind treatment of human asymptomatic carriers of tinea capitis. Databases were searched for the 'tinea capitis', 'carriers' and 'treatment'. Inclusion criteria were clinical trials, observational and interventional studies including case series (10+ cases) and case reports in English, Danish, Swedish, Norwegian and French. Reviews, guidelines, unclear reports and in vitro trials were excluded. A systematic review identified 10 studies with low to moderate evidence levels. The topical treatments ketoconazole, povidone-iodine, miconazole and the systemic antifungals terbinafine and itraconazole have all shown significant effects in the mycological eradication of fungal conidia. General prophylactic hygienic measures may have a benefit. The scientific evidence behind the treatment of asymptomatic carriage of scalp dermatophytes is sparse and not of high quality. Yet, both topical and systemic antifungal agents show treatment efficacy. Considering the possible adverse effects, topical agents are preferable, but with necessary attention to the compliance of asymptomatic contacts with treatment.