Farmer's lung disease: new look and current concepts.

Farmer's lung has been extensively described in the past. However, recent p ublications are progressively modifying our previous and stereotyped approa ch to the disease. These acquisitions concern: 1) the importance of bronchi al involvement with frequent bronchial obstruction and even emphysema as a long-term outcome. 2) the increase in new antigens which, especially, makes difficult the interpretation of the results of precipitins; 3) the key rol e of exposure factors and environmental cofactors, which may be the main ri sk factors for the development and outcome of the disease; and finally 4) f or diagnosis and prognosis, the contribution of chest CT scan, which often shows pathognomonic images, and the possibility for patients to carry on th eir occupation with some precautions. (C) 2001 Editions scientifiques et me dicales Elsevier SAS.