[A Case of Cutaneous Phaeohyphomycosis Caused by Exophiala lecanii-corni Showing a Seasonal Fluctuation of Skin Lesions].

A 56-year-old Japanese female presented to our hospital in March complaining of asymptomatic skin lesions on both cheeks for the past few years. She had been receiving treatment for phlebosclerotic colitis and gastroesophageal reflux disease. We identified subcutaneous nodules with scale, erosion, and necrotic crusts on the surface, with one on the right cheek and two on the left. The patient said that the eruptions almost disappeared every summer but always recurred in winter, a phenomenon that we confirmed. Histopathology revealed pseudoepitheliomatous hyperplasia and marked infiltration from various inflammatory cells with a granulomatous reaction in the dermis. Brown fungal elements were scattered around the epidermis and dermis in the form of single spore or toruloid hyphae. We identified the fungus as Exophiala lecanii-corni based on morphological and physiological characteristics, as well as rRNA gene analysis. The strain grew well at 27 ℃, but growth was remarkably suppressed at 33 ℃ and not observed at all at 37 ℃. Treatment with itraconazole 200 mg / day for 6 months resulted in complete remission of the lesions.