[A clinical study of 5 cases of acute eosinophilic pneumonia--the relationship between beginning to smoke and acute eosinophilic pneumonia].

We encountered 5 cases of acute eosinophilic pneumonia. All cases were young men who had recently begun smoking, and they showed an acute onset hypoxemia, diffuse shadows on chest X-ray, an elevation of eosinophils in the peripheral blood and broncho-alveolar lavage fluid, and rapid recovery. One of the 5 cases showed a re-elevation of eosinophils in the peripheral blood and broncho-alveolar lavage fluid after a smoking challenge test. It appears that one of the causes of acute eosinophilic pneumonia is beginning to smoke.