Chronic bird fancier's lung presenting with acute exacerbation due to use of a feather duvet.

A 67-year-old man was admitted due to fever and exertional dyspnea. He used to raise budgerigars and hill mynahs from 1980 to 1988. He was diagnosed as having chronic bird fancier's lung (BFL) based on a positive peripheral lymphocyte proliferation to pigeon serum in 1994. His disease was stable until 2000. Three months before admission he became a daily user of a feather duvet. A chest CT showed newly-developed peribronchial ground-glass opacities and preexisting honeycombing. Inhalation provocation test was positive. Administration of steroids improved his condition. He has been well after refraining from the use of the feather duvet.