Not many people will have their health on their minds when they go shopping for a new blanket. But after one man in the UK changed his bedding, strange things began to happen.
It began with just a bit of difficulty breathing. After that though, it wasn’t long before he found himself all but gasping for air, and completely void of energy. That on top of dizziness, fatigue, and breathlessness finally brought the 43-year-old to the doctor.

After a misleading bronchitis diagnosis that didn’t see his symptoms improve as they should have, his doctor referred him to an urgent respiratory care clinic – where he wound up in the care of Owen Dempsey, a chest doctor at the Aberdeen Royal Infirmary. Later on, Dempsey would publish the findings of this man’s diagnosis to help others handle such a confusing and urgent situation.
As Dempsey and the breathless man walked backwards through his last few weeks step by step, he finally got to the part where he mentioned blanket shopping with his wife – and landing on a new feathered down duvet and pillow set, replacing his old synthetic one.

That’s when the doctor realized the issue was hypersensitivity pneumonitis (abbreviated as HP).
HP is actually an allergy, but this particular form mostly affects people who raise or work closely with birds, which has earned it the nickname of ‘bird fancier’s lung.” But there are other cases of people getting it from simple exposure to the feathers via bedding or other furniture, which is dubbed ‘feather duvet lung’ instead. If you’re wondering why it didn’t show up on his allergy tests, you’re not alone – and the reason is fascinating, albeit a bit scary.
HP is complex and quite rare, and the body reacts to this presence in the lung differently than it would to things from food or on skin – making it undetectable through a standard allergy test – and it comes on slowly, which makes the stimulus harder to detect. It also seems that while many people will react with these antibodies, only some will become sick, for reasons yet unknown.

But, the doctor says it’s not something to worry about if you’ve already been sleeping with down materials symptom-free..
“Hold onto your feather bedding, but if you do get chest symptoms, e.g. breathlessness or cough, mention it to your health care professional,” Dempsey said. “Most don’t think about it.”