A middle-aged man developed a life-threatening lung condition after buying feather-filled bedding, it has been revealed.

Martin Taylor, from Aberdeenshire, felt so unwell, tired and breathless the simplest activities became a chore - such as going from room to room at home or walking up the stairs.

The 43-year-old was a non-smoker, but had recently swapped a synthetic cover and pillows for feather-filled bedding.

After being referred to Aberdeen Royal Infirmary he was diagnosed by respiratory specialist Dr Owen Dempsey as having hypersensitivity pneumonitis.

The illness, which doctors have called 'feather duvet lung (FDL)' or 'bird fancier's lung (BFL)' is triggered by an allergic reaction to inhaled dust from feathers.

Those affected by the condition see the air sacs and airways in their lungs become severely inflamed.

The married office worker started getting better, as soon as he was told to get rid of his feather duvet and pillows.

Mr Taylor told BMJ Case Reports: "Hypersensitivity pneumonitis had a great effect on my life at the time. I started getting dizzy spells on exertion.

"There was a rapid decline in my health and the lack of a diagnosis after four appointments at the GP surgery was extremely distressing at the.

"Two months after the onset of the symptoms, 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.

"Going upstairs to bed was a 30 minute activity as I could only manage two stairs at a time and then needed to sit and rest."

He was signed off work and spent most of the time asleep - both day and night.

Mr Taylor added: "I am extremely grateful to my local GP for immediately referring my case to Dr Dempsey who quickly diagnosed me with hypersensitivity pneumonitis.

"I understand that it is an allergic reaction in my lungs to something breathed in.

"This reaction has caused my lungs to have reduced efficiency at oxygenating my blood, causing extreme light-headedness."

"You shouldn't crawl into your duvet and be afraid of dying," he later told the Ottawa Citizen newspaper.

Dr Dempsey said his symptoms improved within the first month once he disposed of the bedding, even before starting to take steroid pills.

Mr Taylor was immediately advised to remove it from his bedroom, before the damage to his lungs was identified in CT scans.

Dr Dempsey said: "We also advised him to get his bathroom mould treated and check there were no nesting birds in his loft or chimney."

After being told a possible cause of the allergy was the feather duvet and pillows Mr Taylor replaced them with hypoallergenic bedding. His breathing is now normal and he made a full recovery.

He said: "I have not had any dizzy turns since recovering. It doesn't affect me at all now and my life is pretty much as it was before."

FDL is a form of hypersensitivity pneumonitis caused by an over-reaction of immune cells.

A study by Spanish researchers in 2013 first warned feather pillows and duvets can cause chronic and potentially fatal shortness of breath.

Dr Dempsey said: "Our case reinforces the importance of taking a meticulous exposure history and asking about domestic bedding in patients with unexplained breathlessness.

"Prompt recognition and cessation of antigen exposure may prevent the development of irreversible lung fibrosis (scarring)."

Mr Taylor went to his GP in November 2016 after suffering malaise, fatigue and breathlessness for three months, said Dr Dempsey.

It was initially thought he had a chest infection. His respiratory symptoms got so bad he took two weeks off sick later that month.

His blood, kidneys and liver were normal but by December he could hardly walk.

During a phone interview it turned out Mr Taylor and his wife had a cat and a dog - but no birds.

The researchers pointed out this is just one case. It's not known how common feather duvet lung is. It's often missed as doctors rarely ask patients about feather bedding.

But in the first four months of 2015 alone, seven million duvets were sold in the UK, they point out.

And repeated exposure to the culprit trigger in hypersensitivity pneumonitis can lead to irreversible scarring of the lung tissue, so it's important to identify this promptly, they say.