ACUTE EOSINOPHILIC PNEUMONIA - HISTOPATHOLOGIC FINDINGS IN 9 PATIENTS

Acute eosinophilic pneumonia is characterized by acute respiratory ins ufficiency, hypoxemia, fever, diffuse radiographic infiltrates, and eo sinophilia in bronchoalveolar lavage fluid (BALF) or lung biopsies in the absence of infection, atopy, or asthma. A rapid response to cortic osteroids is characteristic. We reviewed our experience with nine case s of acute lung disease with histologic features of acute and organizi ng diffuse alveolar damage and prominent interstitial and alveolar eos inophils in order to determine whether this pathology was characterist ic of acute eosinophilic pneumonia. The mean age of the patients (four men and five women) was 53 yr (range: 33 to 71 yr). They presented wi th 2 to 21 d of dyspnea, cough, myalgias, and fever. All were hypoxic and had bilateral infiltrates on chest radiographs. Peripheral blood e osinophilia was present in four of eight patients (peripheral blood co unt unavailable for one patient). Ail patients were treated with high- dose corticosteroids with a mean time to symptomatic and radiographic improvement of 4 d. Seven of the nine patients enrolled in the study a re alive without relapse; one patient has a mild deficit in diffusing capacity, and one patient died of a myocardial infarct while improving on therapy. The presence of eosinophils in cases of acute respiratory insufficiency due to diffuse alveolar damage (DAD) should suggest the diagnostic possibility of acute eosinophilic pneumonia. Acute eosinop hilic pneumonia should be distinguished from other causes of DAD becau se of important differences in natural history.