Reported by Shari Barnett, M.D., ABC News Medical Unit:
Rosacea can be annoying, embarrassing and even painful - and now new research shows it could be the result of a type of bacteria that rides into your face in the belly of a mite.
A skin problem that causes reddening and inflammation on the cheeks, nose and chin, rosacea affects approximately 3 percent of Americans. Fair-skinned females between the ages of 30 and 50 are most at risk. Those with impaired immune systems are also disproportionately affected.
Doctors have known for years that rosacea was caused by tiny mites called Demodex folliculorum that usually live in people's facial hair follicles. However, they did not understand why these mites would cause the symptoms of rosacea, nor did they know why treating with antibiotics improves the appearance.
Despite this, doctors have tended to use both oral and topical antibiotics to treat rosacea - despite a causative bacteria never having been identified. That is until recently; when researchers at the National University of Ireland conducted a review that concluded that a bacterium isolated inside the mites called Bacillus oleroni was responsible.
"The bacteria live in the digestive tracts of Demodex mites found on the face, in a mutually beneficial relationship," Dr. Kevin Kavanagh, who conducted the review, explained in a Wednesday news release. "When the mites die, the bacteria are released and leak into surrounding skin tissues, triggering tissue degradation and inflammation."
The researchers found that people who suffered from rosacea had higher rates of these mites than people who did not have rosacea, and thus were exposed to more bacteria. Also, the bacteria produce chemicals that have been shown to cause inflammation in people who suffer from rosacea - and in some cases, exposure to these chemicals actually triggered the condition.
"Once the numbers of mites increase, so does the number of bacteria, making rosacea more likely to occur," Kavanagh writes. "Targeting these bacteria may be a useful way of treating and preventing this condition."
The inflammation and redness that comes along with rosacea poses significant problems for patients, both in terms of appearance and pain. Antibiotics commonly used for the condition often kill these bacteria, but there are still a number of cases of roseacea that remain hard to treat.
The findings of this new study could open the doors to new insights - and even novel treatments - for this sometimes difficult condition.
"It is interesting that they have identified this bacteria and it holds the potential to develop more targeted therapy of the treatment of roseaca," says Dr. Mathew M. Avram, director of the Massachusetts General Hospital Dermatology Laser & Cosmetic Center, who was not involved with the study.