Idiopathic acute eosinophilic pneumonia.

A previously healthy young man presented with acute respiratory distress, high fever and bilateral ground-glass appearance on chest radiograph. Bronchoalveolar lavage analysis demonstrated significant eosinophilia (72%) with no evidence of infection. The transbronchial lung biopsy showed that the walls of bronchioli and alveolar septa were markedly infiltrated with eosinophils. The patient rapidly improved with corticosteroid therapy. This case exemplifies the recently described idiopathic acute eosinophilic pneumonia. Similar cases published in the Japanese literature were reviewed and discussed.