Airborne Fungus May Cause Chronic Stuffy Nose

Oct. 8, 2004 -- Scientists may be one step closer to understanding why some people have chronic stuffy noses. An overblown immune system response to a common fungus may be the reason.

Most people get stuffy noses only occasionally.

However, chronic stuffy nose is common enough to cost about $5.6 billion per year and account for some 70 million annual sick days.

Antibiotics, antihistamines, and surgery usually don't solve chronic stuffy nose, the causes of which are not thoroughly understood, say the researchers.

The study was conducted by Hirohito Kita, MD, and colleagues from the Mayo Clinic in Rochester, Minn., along with experts from the University of Utah. Their findings are reported in today's online edition of the Journal of Allergy and Clinical Immunology.

Finding May Help Fight Chronic Stuffy Nose

Kita's team compared the immune system responses of 18 people with chronic stuffy nose and 15 people without the condition.

They tested participants' blood samples to see how specific immune system cells responded to common airborne fungi.

The researchers also analyzed nose secretions from nine people with chronic stuffy nose and nine healthy people.

The results showed different degrees of immune system response between those with chronic stuffy nose and those without.

The people with chronic stuffy nose had an exaggerated immune response to the fungi, compared with the healthy participants.

That could explain the airway inflammation, thick mucus production, loss of smell, and other symptoms seen with chronic stuffy nose.

In particular, a fungus called alternaria provoked an exaggerated immune response in about 90% of participants with chronic stuffy nose.

A second fungus, called cladosporium, also triggered an immune system overreaction in the chronic stuffy nose group.

Both fungi can be found wafting through the air "anywhere in the U.S.," says Kita in a news release.

Most people breathe in the fungi without ever realizing it, but others may be more sensitive.

The findings could lead to new treatments for chronic stuffy nose.

"Now that we know the role of the fungi, we can work toward reducing the potential role of the fungi through such treatments as nasal irrigations (flushing with water) that clear the fungi, or prescription of antifungal medications taken by mouth," says Kita in a news release.

Nasal irrigation has shown promise in preliminary tests but requires larger studies before being recommended for general use in people with chronic stuffy nose, according to the news release.