ROCHESTER, MINN. -- Mayo Clinic researchers say they have found the cause of most chronic sinus infections -- an immune system response to fungus. They say this discovery opens the door to the first effective treatment for this problem, the most common chronic disease in the United States.
An estimated 37 million people in the United States suffer from chronic sinusitis, an inflammation of the membranes of the nose and sinus cavity. Its incidence has been increasing steadily over the last decade. Common symptoms are runny nose, nasal congestion, loss of smell and headaches. Frequently the chronic inflammation leads to polyps, small growths in the nasal passages which hinder breathing.
"Up to now, the cause of chronic sinusitis has not been known," say the Mayo researchers: Drs. David Sherris, Eugene Kern and Jens Ponikau of the Department of Otorhinolargygology (ENT) at Mayo Clinic. Their report appears in the September issue of the journal Mayo Clinic Proceedings.
"Fungus allergy was thought to be involved in less than ten percent of cases. Our studies indicate that, in fact, fungus is likely the cause of nearly all of these problems. And it is not an allergic reaction, but an immune reaction."
The researchers studied 210 patients with chronic sinusitis. Using new methods of collecting and testing mucus from the nose, they discovered fungus in 96 percent of the patients' mucus. They identified a total of 40 different kinds of fungi in these patients, with an average of 2.7 kinds per patient.
In a subset of 101 patients who had surgery to remove nasal polyps, the researchers found eosinophils (a type of white blood cell activated by the body's immune system) in the nasal tissue and mucus of 96 percent of the patients.
The results, the researchers say, clearly portray a disease process in which, in
sensitive individuals, the body's immune system sends eosinophils to attack
fungi and the eosinophils irritate the membranes in the nose. As l
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Contact: Mike O'Hara
newsbureau@mayo.edu
507-284-9522 (days)
Mayo Clinic
9-Sep-1999