Current topics in diagnosis and treatment of tinea unguium in Japan

The number of patients with tinea unguium accounts for 0.5% to 2% of the total number of outpatients in Japan. The diagnosis of tinea unguium can be relatively easily made on the basis of clinical symptoms and direct microscopic findings. However onychomycosis due to fungi other than dermatophytes should always be suspected if no dermatophytes are cultured despite positive findings in direct microscopy. In such cases, it is necessary to repeat cultures and conduct histopathological evaluation using PAS-staining technique or enzyme antibody technique. At present, oral administration of griseofulvin and terbinafine are the treatments covered by health insurance in Japan. In the future, however, other orally active antifungal drugs such as itraconazole and fluconazole will become available for use by in-patients who do not respond to griseofulvin. It is essential to patiently continue treatment even if oral therapy is impossible, because other therapies such as ODT therapy using topical antifugal agents and urea ointment or abrading affected nails as much as possible with a file or dental drill may be effective without oral therapy.