Hypersensitivity pneumonitis induced by spores of Pholiota nameko.

A 42-year-old man experienced recurrent episodes of nonproductive cough, fever, and dyspnea on exertion. He had worked as a mushroom farmer for 10 years. The diagnosis of hypersensitivity pneumonitis was confirmed immunologically by detecting a precipitin to spores of Pholiota nameko but not to other antigens. After separation from the antigen along with an addition of corticosteroid therapy, the symptoms, inflammatory findings and a reduced level of PaO2 quickly subsided.