POSSIBLE INVOLVEMENT OF AN ENVIRONMENTAL AGENT IN THE DEVELOPMENT OF ACUTE EOSINOPHILIC PNEUMONIA

Background: Although the pathogenesis of acute eosinophilic pneumonia remains largely unknown, it has been suggested that it may include a h ypersensitivity phenomenon induced by inhaled environmental antigens. Methods: To investigate this possibility, we studied the effect of env ironmental challenges in three patients with acute eosinophilic pneumo nia. Symptoms and laboratory findings were evaluated before and after the challenge tests in the patient's homes and their places of work. R esults: After the provocation challenges to their homes, all three pat ients developed fever, cough, and fatigue and two of them presented wi th dyspnea. Inspiratory crackles became audible in all cases, and ther e was a decreased Pao2 level in two. Similar challenges at their workp laces were negative. After moving out of their homes, the patients eng aged in their usual work but had no recurrent episodes. Conclusions: T hese results suggest that environmental factors in the home can be the cause of acute eosinophilic pneumonia. In order to elucidate the path ogenesis of the disease, it is important to further investigate enviro nmental factors.