[Present state and future direction of topical antifungals]

Topical agents are generally better than oral medicine with respect to systemic side effects. Even if an antifungal drug causes severe systemic side effects, the drug, if it has excellent antifungal activity, can be used for topical treatment. In addition, because most causative fungi in dermatomycosis are usually located in the horny cell layers of the epidermis (superficial layers of the skin), topical antifungals are the first choice of treatment for most dermatomycoses. Many topical antifungals with excellent antifungal activity have recently been developed and once a day topical application is presently possible. In spite of these new agents, however, clinical efficacy and mycological eradication rates have not shown significant improvement and there are still many patients with tinea pedis. One reason that no significant improvement has been observed in the topical antifungal therapy may be due to poor compliance with the treatment. That is, because it is difficult for most patients to continue regular topical application for a long period, most usually stop treatment after clinical symptoms disappear, even though no mycological cure may yet have been achieved. In addition, topical antifungals are not effective for the treatment of hyperkeratotic skin lesions or nail and hair infection. Therefore, the goal of new topical antifungals should be good compliance, which means shortening of the treatment period, high penetration of the drug into horny cell layers, nails, and hair, and high affinity to horny cell layers in order to keep a high concentration of the drug within the lesions.