A disease of unknown cause in which eosinophilic material is deposited in the alveoli. The principal symptom is dyspnea. Death from pulmonary insufficiency may occur, but complete recovery has been observed. There is no specific treatment, but general supportive measures including antibiotics and bronchopulmonary lavage have helped. In about 25% of cases, the disease clears spontaneously, but in most untreated cases the disease is progressive and leads to respiratory failure.