ABSTRACT
A 41-year-old Japanese-Brazilian man, living in Japan since 1991, visited our hospital in August 1998 complaining of a scaly annular erythema which had been present on his right forearm since 1996. Granulomatous inflammation was revealed in the dermis upon skin biopsy. Sclerotic cells were present within the granulomatous lesions. Fonsecaea pedrosoi was isolated from tissue cultures. The restriction fragment length polymorphism pattern of mitochondrial DNA of the causative fungus was compatible with F. pedrosoi type 1, the commonest type in Japan. Since type 4 is usually found in South America, the patient was assumed to have become infected in Japan. An oral dose of terbinafine at 125 mg/day was ineffective. 125 mg/day single dose of terbinafine reaches an average plasma concentration of only 0.69 g/ml, where as 250 mg/day reaches 0.96 micro g/ml. Because the minimum inhibitory concentration (MIC) of terbinafine against the isolated fungus was found to be 0.76 micro g/ml, the terbinafine dose was increased from 125 mg/day to 250 mg/day, which slowly led to remission. Chromomycosis is caused by several species of dematiaceous fungi, and terbinafine efficacy may vary depending on the causative fungus. MIC values may differ even within the same species. It is important to isolate the pathogenic fungus in each case and measure the MIC value to determine the optimal dose of terbinafine.