Abstract
Four mushroom workers have developed an extrinsic allergic alveolitis, after working with the oyster mushroom (Pleurotus ostreatus). After provocation with aerosolized spores under laboratory conditions, the four patients showed the complaints of an extrinsic allergic alveolitis; a rise of body temperature, leucocytosis and changes of lung function parameters were observed. Antibodies against the spores were assessed in the blood of these patients.