[Usefulness of pathological diagnosis for two cases of candidal onychomycosis].

We report two cases of candidal onychomycosis with severe nail deformities. Case 1: The patient was an 81-year-old man who complained of onycholysis and nail deformity of the right forefinger nail which had occurred over a period of a year. He had no obvious previous illness. Case 2: The patient was an 81-year-old woman who complained of nail deformity with periungual erythema which had occurred over a period of several months. She had been treated with oral corticosteroid for bronchial asthma and with Ca blocker for hypertension for a long period. The initial KOH-prepared direct microscopy in each case failed to detect any spores or pseudohyphae. Therefore, an incisional biopsy was performed in both cases. Histopathological findings demonstrated numerous fungal elements with similar appearance of dermatophytes in the middle to lower level of the horny cell layer by PAS and Grocott staining in each case. Candida albicans was isolated and identified by cultivation on ATG agar. In case 1, oral itraconazole (100 mg/day) was administered for 14 weeks, which was effective clinically and mycologically. In case 2, however, a coadministered drug (Ca blocker), oral terbinafine (125 mg/day) was not effective mycologically. Therefore, after having changed the antihypertensive agent, oral itraconazole (100 mg/day) was administered for 16 weeks, which was effective clinically and mycologically.