Hypersensitivity pneumonitis caused by isocyanate exposure during recreational painting

: A 36-year-old man began painting his car as a hobby every weekend in early February 2007 using a paint containing isocyanate. In March, 2007, he developed a dry cough, dyspnea and fever of 40 degrees C. These symptoms appeared repeatedly several hours after engaging in painting activity. His chest X-ray film showed diffuse small granular and reticular shadows in bilateral lung fields. His computed tomogram showed ground glass images in bilateral lung fields. Pulmonary function tests showed significantly decreased DLco. Histological findings of transbronchial lung biopsy revealed cellular interstitial pneumonia. These symptoms improved after cessation of painting and administration of prednisolone. Based on these results, we diagnosed this patient's illness as hypersensitivity pneumonitis due to isocyanate exposure.