[Case of acute exacerbation after video-assisted thoracoscopic surgery in a patient with chronic hypersensitivity pneumonitis].

: A 65-year-old man had been admitted with exertional dyspnea 2 years previously. Reticular shadows in bilateral lower lung fields were detected on chest roentogenogram and observed the natural course. The clinical symptoms and radiological findings progressed one month later and then he was admitted to our hospital to be examined for diagnosis and treatment. Video-assisted thoracoscopic surgery (VATS) was performed and chronic hypersensitivity pneumonitis was diagnosed. At five days after the surgery, dyspnea and radiological findings deteriorated and we diagnosed acute exacerbation of chronic hypersensitivity pneumonitis. He was treated immediately with steroid pulse therapy, immunosuppressant and polymyxin B-immobilized fiber column-direct hemoperfusion, which relieved his clinical symptoms and radiological findings. Although this is a very rare case, we have to consider the possibility of acute exacerbation of chronic hypersensitivity pneumonitis after VATS, as we do in idiopathic pulmonary fibrosis.