LAUSR

DEAR EDITOR, An 84-year-old Japanese man presented with (a) papules on the right wrist and dorsum of the hand. A skin biopsy revealed (b) non-necrotizing granulomas with 4–6lm-sized microorganisms stained with (c) Grocott and periodic-acid–Schiff PAS. Polymerase chain reaction (PCR) of a sample of fresh skin was performed with the panfungal primers ITS3 and ITS4, which detected Desmodesmus sp. F18. Additionally, PCR of paraffin sections of the skin biopsy confirmed Desmodesmus sp. The lesions disappeared after 3 months of internal itraconazole treatment. Infection with Desmodesmus, a chlorophyll-containing alga, is extremely rare. The discovery of small, yeast-like forms with broad-based buds may be a hint to perform molecular analysis.