extrinsic allergic alveolitis (EFO_1001321, an Experimental Factor Ontology term) is a common interstitial lung disease caused by hypersensitivity reactions of PULMONARY ALVEOLI after inhalation of and sensitization to environmental antigens of microbial, animal, or chemical sources. The disease is characterized by lymphocytic alveolitis and granulomatous pneumonitis. Also known as: Alveolitis, Extrinsic Allergic.