Researchers Find Rosacea Cause that Will Modify Treatment Approach

A news release says researchers have found what causes rosacea, an inflammatory skin disease also sometimes called "adult acne." Although the triggers and symptoms are easy to identify, not until now has the real cause been understood.

Richard L. Gallo, M.D., Ph.D., Professor and Chief of the Division of Dermatology, University of California - San Diego, is a leading investigator in the field of skin research. He led the team of researchers that discovered by animal experimentation and work in the laboratory that a combination of two abnormal factors result in rosacea.

In the news release, Dr. Gallo said: "It's like having lots of gasoline...and a match." Excess production of two interactive inflammatory proteins results in too much of a third protein that then causes rosacea symptoms. It's "a trifecta of unfortunate factors in people with rosacea," he said.

In the study, the researchers noted that anti-microbial peptides caused the same symptoms that rosacea causes: redness, visible blood vessels, bumps, pimples. Gallo said that "when we then looked at patients with the disease, every one of them had far more peptides than normal."

The next step was to determine why these individuals had more peptides than most other people. The researchers looked at the source or precursor to the peptides, which is cathelicidin. Cathelicidin is usually known for its ability to protect the skin from infection. If a person has a cathelicidin deficiency, infection generally increases. In the case of rosacea patients, however, Dr. Gallo and his team found that they had too much cathelicidin in their skin. The researchers also found that the cathelicidin in rosacea patients was a different form than that found in people without the disease.

They also observed that patients with rosacea had very high levels of stratum corneum tryptic enzymes (SCTE), which were responsible for turning the cathelicidin into the disease-causing peptide.

They proved their observations by injecting mice with the cathelicidin peptides found in rosacea, or adding SCTE. This resulted in an increase of inflammation in the mouse skin.

Rosacea, unlike acne, isn't caused by a bacteria, although antibiotics are often prescribed to treat its infection-like symptoms. However, antibiotics and other current treatments are usually ineffective over the long term because they do not get at the cause.

In the news release, Dr. Gallo said of their findings: "Too much SCTE and too much cathelicidin leads to the abnormal peptides that cause the symptoms of this disease. 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."

The next step for researchers is to determine how to effectively address and treat the actual cause of rosacea.

Source:

News release, Researchers Discover Cause of Rosacea; http://www.newswise.com/articles/view/532010/