[Mushroom grower's lung. Apropos of 3 cases].

Three cases of mushroom growers lung, responding to the criteria for an extrinsic allergic alveolitis, have been observed in the Hôpital Bichat, Paris. In the first case, a "semi-delayed" hypersensitivity phenomenon of type III was evoked, an "immediate" type I phenomenon in case 2, and an association of the two in the third case. Clinical manifestations may develop very rapidly in subjects working in areas where they are exposed to a high inoculum of fungal products. Multiple antigens are involved: Psalliota, actinomycetes of different varieties, manure substrate, fungal spores, bacteria, cereal dust, etc. A recognized occupational disease, it leads to a change in activity and the right to compensation.