What is acute eosinophilic pneumonia?

Acute respiratory failure with increased BAL/ eosinophilia , could be hypersensitivity rxn or drug toxicity. Acute febrile illness (5 days duration), hypoxemic respiratory failure, alveolar and interstitial infiltrates, BAL eosinophilia, no infection, rapid complete resolve with corticosteroids, no relapse after stopping steroids Presents with fever, malaise, myalgia, pleuritic pain, hypoxemia, require ventilation (like ARDS) BAL provides clue (blood eosinophils normal) Pleural effusion frequent Response rapid to steroids (24-48 hours) first high dose then tempered the dose, given for 2-4 weeks Dx of exclusion