Leflunomide-Induced Interstitial Lung Disease: A Case Report

Leflunomide (LEF) induced interstitial pneumonitis is a very rare condition but potentially fatal. We report a case of LEF induced interstitial pneumonitis. A 63-year-old woman followed-up for 37 years with the diagnosis of rheumatoid arthritis treated with LEF (20 mg/day) since 5 months were admitted to our hospital with cough, dyspnea, fever, and dark sputum.Chest radiography represented bilateral alveolar consolidation. High-resolution computed tomography demonstrated diffuse ground-glass appearance and interlobular septal thickening. Since the patient’s clinics and radiologic findings improved dramatically after the cessation of LEF and recieving oral steriod therapy, she was diagnosed as drug-induced interstitial lung disease. In conclusion, when nonspecific clinical signs such as respiratory distress, cough and fever seen during the use of LEF, drug-induced interstitial lung disease should be kept in mind for the differantial diagnosis.