Bronchiolitis associated with exposure to artificial butter flavoring in workers at a cookie factory in Brazil

To report the cases of four patients with bronchiolitis caused by exposure to artificial butter flavoring at a cookie factory in Brazil. We described the clinical, tomographic, and spirometric findings in the four patients, as well as the lung biopsy findings in one of the patients. All four patients were young male nonsmokers and developed persistent airflow obstruction (reduced FEV1/FVC ratio and FEV1 at 25-44% of predicted) after 1-3 years of exposure to diacetyl, without the use of personal protective equipment, at a cookie factory. The HRCT findings were indicative of bronchiolitis. In one patient, the surgical lung biopsy revealed bronchiolitis obliterans accompanied by giant cells. Bronchiolitis resulting from exposure to artificial flavoring agents should be included in the differential diagnosis of airflow obstruction in workers in Brazil.