By David Beasley

DENVER-- Rosacea, a skin condition that produces red facial splotches and sometimes disfiguration of the nose, doesn’t discriminate on the basis of fame.

President Bill Clinton and the late actors Karl Malden and W. C. Fields all suffered from the disease, as do some 16 million more ordinary Americans.

-graph source: National Rosacea Society

While sufferers do have some characteristics in common — the disease occurs most often in patients with Northern European heritage, especially women over 30 and men over 40, with special prevalence in those with Irish ancestry — the cause of the disease remains a mystery.

Now, new research is beginning to point scientists in novel directions as they try to develop a cure.

The exact cause of rosacea has long been a mystery, although genetic makeup has provided some clues.

“The vast majority of it is genetic predisposition,” said Robert Dellavalle, MD, chief of dermatology at the Denver VAMC. A 2008 survey by the nonprofit group, the National Rosacea Society, found that 54% of patients with the condition had a family member who also had it.

Yet, although many rosacea patients may have inherited the condition, only in a tiny portion of patients have scientists identified a genetic defect, added Richard Gallo, MD, head of dermatology at the San Diego VAMC. “There is not a single genetic defect in most patients.”

Researchers have looked for other indicators, and a recently published study led by Gallo and funded by a grant from the National Rosacea Society points to a protein in the skin called cathelicidin as the culprit.¹

That study found that patients with rosacea had cathelicidin levels 100 times higher than those without the disease. Cathelicidins are necessary to prevent skin infections, but rosacea patients have “way too much of it,” Gallo said in a recent interview with U.S. Medicine.

That might explain why the antibiotic doxycycline can help control the condition, according to Gallo, who noted that doxycycline, approved by the FDA in 2006 for treatment of rosacea, blocks the production of cathelicidins.

“But it’s not effective for everyone,” he noted. “In some patients, it makes it worse.”

Gallo said the goal of more research is to find a drug that can actually cure rosacea, not simply control its symptoms for some patients.