Clinical evaluation of 12 cases of antimicrobial drug-induced pneumonitis.

The diagnosis of drug-induced pneumonitis is generally difficult, and it is made clinically by Tamura's criteria. We experienced 12 cases (7 definite and 5 possible cases) of antimicrobial drug-induced pneumonitis (one of case was the first case caused by carbapenem). Symptoms such as fever (11/12), cough (10/12) and dyspnea (10/12) and laboratory data such as eosinophilia (7/12), elevation of IgE (4/6) and hypoxia (11/12) were commonly seen in these patients, although they were not specific. Lymphocyte stimulation test (5/11) and provocation test (4/8) were quite suggestive of drug allergy. Bronchoscopy has been used for confirmation of pneumonitis. Transbronchial lung biopsy revealed alveolitis (4/9) or alveolar fibrosis (3/9), and bronchoalveolar lavage showed lymphocytosis (6/6) and depression of OKT4/T8 ratio (3/5). The combination of bronchoscopic and immunological examinations were more confirmative for diagnosis.