[A case of chromomycosis caused by Fonsecaea pedrosoi presenting as a small plaque on the left upper arm: a review of reported cases of dematiaceous fungal infection in Japan].

We report a case of a 67-year-old woman with chromomycosis on the left upper arm. The plaque was a very small, erythematous and scaly lesion with a diameter of 1.5 cm. Fonsecaea pedrosoi was isolated as the causal fungus, and a number of Phialophora type conidia, the formation of which is considered rare, were observed. Treatment involved surgical excision of the lesion with a 5 mm margin. Follow up three years later revealed no recurrence. In Japan, 536 patients with chromomycosis were reported from 1955 to 2004. This consisted of 296 cases from 1955 to 1981 as reported by Fukushiro, and 240 cases from 1982 to 2004 as reviewed by us. Our examination of data showed that the most common causal fungi was F. pedrosoi with 137 cases (57.15%), followed by Exophiala jeanselmei with a total of 41 cases (17.15%), other fungal species comprised of 16 cases (6.7%), Phialophora verrucosa in 9 cases ( 3.8%) and E. dermatitidis in 4 cases (1.7%). Compared to the previous report by Fukushiro, the incidence of infection with E. jeanselmei had increased. Of the 235 cases we reported, the site of infection involved: upper extremities in 91 (38.7%), face and neck in 42 (17.9%), buttocks in 41 (17.4%), lower extremities in 33 (14%) and body in 23 (9.8%). Compared to Fukushiro's report, cases affecting the lower extremities had decreased, whilst cases involving the buttocks had increased. Overall, the treatment for chromomycosis was either oral administration of antifungal agents, excision, thermotherapy, or a combination of these methods.