Pathogenesis and treatment of hyperkeratotic tinea pedis in Japan

Abstract

In this paper, we describe the major characteristics of hyperkeratotic tinea pedis and review therapeutic results obtained in the Department of Dermatology of Kitasato University Hospital and those reported in the literature in Japan and abroad.

Usefulness of 1% terbinafine HCl (Lamisil®) cream for hyperkeratotic‐type tinea pedis and its transfer into the horny layer

“…It is generally believed that hyperkeratotic‐type tinea pedis is extremely difficult to cure by topical antifungal agents alone due to their poor penetration into lesions. In Japan therefore oral administration of griseofulvin has been commonly used to treat tinea pedis of this type, but griseofulvin is now gradually being replaced by itraconazole [1]. However, oral administration of antifungal agents is not possible in all patients due to various problems such as gastrointestinal and hepatic dysfunction and interactions with other drugs.…”

“…Hyperkeratotic‐type tinea pedis is a refractory disease characterized by proliferation of the stratum corneum in the soles. In Japan, it is generally classified into three types: true hyperkeratotic‐type, partial hyperkeratotic‐type, and quasi‐hyperkeratotic type [1]. The true hyperkeratotic‐type is extremely rare, and hyperkeratotic‐type tinea pedis with marked hyperplasia of the horny layer (partial hyperkeratotic‐type or quasi‐hyperkeratotic type) is the type that is most often encountered in daily medical practice [1].…”

“…Oral antifungal agents, such as griseofulvin, have mainly been used to treat this disease, but no topical antifungal agent has been regarded as effective enough to cure the disease when used alone [1]. Recently, however, a number of topical antifungal agents with strong antifungal activity which penetrate into and remain at high concentrations in the stratum corneum have been developed, and we found that some of them are quite effective when treatment is continued under appropriate medical guidance [1–3].…”

Usefulness and pharmacokinetic study of oral terbinafine for hyperkeratotic type tinea pedis

“…As hyperkeratotic type tinea pedis creates remarkable keratinization, topically applied antifungals do not penetrate the stratum corneum deep enough. Therefore, antifungal treatment is often unsuccessful when topical antifungal is used alone 1–4 . For this reason, oral antifungals such as griseofulvin (GRF) have long been prescribed as the first choice of drug to treat this disease 4 …”

“…For convenience, hyperkeratotic type tinea pedis was classified into three types: true‐, partial‐ and quasi‐hyperkeratotic types, as previously described 4,6 …”