A CLINICAL-STUDY OF IDIOPATHIC EOSINOPHILIC PNEUMONIA

To better characterize idiopathic eosinophilic pneumonia (IEP), we stu died the clinical and laboratory features of 27 patients. Patients wit h IEP could be divided into those with chronic eosinophilic pneumonia (CEP) (n=14) and acute eosinophilic pneumonia (AEP) (n=13). CEP was ch aracterized by (1) multiple and dense areas of consolidation on chest radiographs and computed tomographic (CT) scans, (2) persistent sympto ms, (3) a requirement for steroid therapy, and (4) possible relapses. On the other hand, AEP was characterized by (1) diffuse ground-glass a nd micronodular infiltrates on radiographs and CT scans (in mild cases , the lesions were sparse or localized), (2) acute onset with high fev er, (3) spontaneous improvement, and (4) no relapse. In addition, peri pheral blood eosinophil count was significantly higher in patients wit h CEP than in patients with AEP at the first examination. However, the eosinophil fraction also became markedly elevated during the subseque nt courses of AEP. Analysis of bronchoalveolar lavage fluid revealed t hat the percentage of eosinophils was higher in patients with CEP than that in patients with AEP, whereas the percentage of lymphocytes was significantly greater in patients with AEP than patients with CEP. It was also noted that 75 percent of patients with CEP and 82 percent of patients with AEP had allergic diathesis, suggesting that both conditi ons are likely to occur in atopic individuals.