Duck fluff and feathers in the middle of a drying process after being cleaned, in order to be used in duvets and jackets. Photo : Getty Images

A UK man’s innocent decision to change his bedding caused him to develop a strange, rare condition that left him gasping for air, his doctors say. In a new case study out Monday, they detail how the man came down with a rare form of allergy to the bird feathers that filled his new duvet and pillows.


According to the study, published in BMJ Case Reports, the 43-year-old man had suffered months of dizziness, fatigue, and breathlessness by the time he visited his local doctor in November 2016.

At first, his doctor assumed he had a lower respiratory tract infection, like bronchitis, and his symptoms did improve soon after . But by December, they worsened, to the point where he could no longer walk to the next room in his house without feeling out of breath. His doctor referred him to an urgent respiratory care clinic and sought out advice from one of the study authors, Owen Dempsey, a chest doctor at the Aberdeen Royal Infirmary.


“Their immune system behaves in an exaggerated fashion—think Donald Trump rather than Barack Obama”

Dempsey talked with the man over the phone, trying to zero in any potential causes for his symptoms. And once the man mentioned that he and his wife had recently switched from synthetic bedding to a feather duvet and feather pillows, Dempsey quickly came up with a preliminary diagnosis that was later confirmed by lab testing: hypersensitivity pneumonitis, or HP.

The man had a particular form of HP that tends to strike people who raise or work closely with birds, which has earned it the nickname of “bird fancier’s lung.” But in cases where people have gotten HP simply from being exposed to feather bedding, it’s instead been dubbed “feather duvet lung.”

“In some individuals that meet proteins from bird droppings or dust from their feathers, their immune system behaves in an exaggerated fashion—think Donald Trump rather than Barack Obama,” Dempsey told Gizmodo by email .


HP, as Gizmodo very recently explained, is a complex and rare condition. It involves different antibodies than the ones that cause a typical food or skin allergy. That means it isn’t detectable through a standard allergy test, nor do people react instantaneously when they’re exposed to their trigger. It’s also not clear why any one person develops HP, since many of us can carry these specific antibodies to a trigger but never become sick.


“Most people of course don’t get this, and it depends on how their immune system is primed and is affected by their genetics,” Dempsey said.

Because Dempsey quickly suspected feather duvet lung, though, he told the man to remove the bedding from his home the very first time they spoke. And within days, he began to improve. Subsequent treatment with steroids seemed to speed up his recovery, though Dempsey noted there’s no definitive evidence that steroids will help with HP. Regardless, by the time he was weaned off treatment a year later, he was back to normal.


“It doesn’t affect me at all now and my life is pretty much as it was before,” the man wrote in a patient perspective accompanying the case report.

While it’s likely that more people contract feather duvet lung than is documented , given how hard it is to diagnose, it’s not something you should be worried about if you’ve been sleeping contently under a down-filled duvet with no issues.


“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.”