pulmonary infiltrate with eosinophilia (PIE), a hypersensitivity reaction characterized by infiltration of alveoli with eosinophils and large mononuclear cells, edema, and inflammation of the lungs. The simplest form of the condition, in which patchy, migratory infiltrates cause minimal symptoms, is a self-limited reaction elicited by helminthic infections and by certain drugs, such as paraaminosalicylic acid, sulfonamides, and chlorpropamide. A more prolonged illness, characterized by fever, night sweats, cough, dyspnea, weight loss, and more severe tissue reaction, occurs in certain drug allergies and in bacterial, fungal, and parasitic infections. Tropical eosinophilia with paroxysmal nocturnal asthma, dyspnea, cough, low-grade fever, and malaise is related to filarial infection and may occur in long-standing asthma and periarteritis nodosa. See also Löffler’s syndrome.