August 7 (HealthDay News) -- A combination of two abnormal factors cause the common inflammatory skin condition rosacea, a new U.S. study says.

Rosacea, a chronic condition that causes facial redness, affects about 14 million Americans. Triggers -- such as heat, alcohol, spicy foods and embarrassment -- that can worsen the condition are well known. But this is the first study to identify the actual cause of rosacea, the researchers said.

The researchers concluded that overproduction of two interactive inflammatory proteins leads to excessive levels of a third protein that causes rosacea symptoms.

"Too much SCTE (stratum corneum tryptic enzymes) and too much cathelicidin leads to the abnormal peptides that cause the symptoms of this disease," team leader Dr. Richard L. Gallo, professor of medicine and chief of the division of dermatology at the University of California, San Diego School of Medicine, said in a prepared statement.

"Antibiotics tend to alleviate the symptoms of rosacea in patients, because some of them work to inhibit these enzymes. Our findings may modify the therapeutic approach to treating rosacea, since bacteria aren't the right target," said Gallo.

The study results were published in the Aug. 5 online edition of the journal Nature Medicine.

SOURCE: University of California, San Diego Health Sciences, news release, Aug. 5, 2007