A news report details the case of a woman whose bird feather allergy led to shortness of breath and a drop in blood oxygen levels.

The COVID-19 test was negative, but a CT scan finally provided an answer. Berger had a rare but potentially life-threatening reaction to an allergen in her home: bird feathers. For six years, she’d been a volunteer at a wildlife rescue, tending to injured birds. Berger brought some of them home to give them better care and some of those pigeons and doves became her pets. About 10 lived in the house. A couple of dozen more lived in an aviary outside.

Berger’s diagnosis: hypersensitivity pneumonitis, also known as bird fancier’s lung when it’s caused by breathing in particles from bird feathers or droppings. Some people even react to feather pillows or down comforters.

The condition is an inflammatory reaction of the lung when it’s exposed to antigens — different types of proteins that can be found in the environment, said Dr. MeiLan Han, a spokesperson for the American Lung Association and professor of medicine in the division of pulmonary and critical care at the University of Michigan.

“Birds and hot tubs are the two biggest culprits that I see in my practice for potential issues in the home,” said Han, who was not treating Berger.

“(The inflammation) will lead to shortness of breath and oxygen levels dropping. During a pandemic, if you see a funny shadow on an X-ray or CT scan, plus oxygen levels dropping, it makes a lot of sense that people jump immediately to the thing that’s on everyone brain right now, which is COVID-19.”

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