diffuse hypersensitivity pneumonia, an immunologically mediated inflammatory reaction in the lungs induced by exposure to an allergen or a drug. Allergens that trigger the reaction may be derived from fungi, bird excreta, porcine or bovine proteins, wood dust, and fur. Drugs that induce hypersensity pneumonia include chlorproPAMIDE, hydrochlorothiazide, mecamylamine, mephenesin, methotrexate, nitrofurantoin, paraaminosalicylic acid, and penicillin. The disorder is characterized by cough, fever, dyspnea, malaise, pulmonary edema, and infiltration of the alveoli with eosinophils and large mononuclear cells. Also called allergic alveolitis, allergic interstitial pneumonitis, extrinsic allergic pneumonia. See also bagassosis, pulmonary infiltrate with eosinophilia.
