Abstract
A 62-year old man was admitted because of cough and fever. Chest X-ray and CT scan showed ground- grass opacity in the bilateral lungs. Initially he was diagnosed as community-acquired pneumonia and his symptoms were improved by intravenous antibiotics. He developed fever and exercise-induced dyspnea at home on the day of discharged. The BALF findings were compatible with hypersensitivity pneumonitis. Although his symptoms and laboratory data were improved after admission, recurrence happened when the patient went home, even though his house had been cleaned. A serum antibody test against Trichosporon asahii was negative. It was revealed that second-hand humidifier had been used for half a year. A provocation test using the humidifier induced fever and increased peripheral WBC count and serum CRP. A diagnosis of humidifier lung was confirmed by these findings. The serum precipitation test was positive for Candida albicans. No recurrence occurred after he stopped using the humidifier.
https://ror.org/01300np05 
