London - A man suffering from severe breathing problems was diagnosed with "feather duvet lung" after switching his bedding.
The otherwise healthy 43-year-old suddenly became constantly exhausted and could barely climb the stairs without running out of breath.
For months, doctors struggled to diagnose his lung damage – until he told them he had recently changed his bedding.
The man, whose story has been published anonymously in the journal BMJ Case Reports, was diagnosed with swelling inside his lungs caused by the feathers in his duvet and pillows after switching from synthetic bedding.
Doctors said a similar problem was sometimes seen in bird keepers. He began breathing normally after taking steroids and removing the feather bedding from his room.
The patient said: "There was a rapid decline in my health... I was unable to stand or walk for more than a few minutes at a time without feeling like I was going to pass out."
The doctors who treated the man, led by Dr Owen Dempsey at Aberdeen Royal Infirmary, said it was unknown how many people might suffer from "feather duvet lung" as doctors tend not to ask people about the bedding they use and the condition is likely to be mistaken for something else.
The man was diagnosed with hypersensitivity pneumonitis, an immune or allergic reaction to repeatedly breathing in irritating particles – in this case, dust from the feathers. It causes swelling which narrows the airways and can trigger a cough or make it hard to breathe.