Scientists may be zeroing in on the cause of the skin condition rosacea – and it might involve mites.

Rosacea, an inflammation of facial skin (typically that around the nose, chin and cheeks), affects about 3 percent of the adult population worldwide, mostly fair-skinned women ages 30 to 50, according to the paper. It’s three times as common among women than men, the paper notes, but men tend to have more severe cases. The condition can range in severity from reddening of the skin to lesions and permanent disfigurement of the skin.

A review of existing research conducted by scientists at the National University of Ireland and published online Aug. 29 in the Journal of Medical Microbiology suggests that rosacea may be caused by bacteria carried in the digestive tracts of a species of mite that populates human facial skin.

You probably didn’t know (and would perhaps prefer not to find out) that a worm-like species of mite known as Demodex folliculorum resides around the hair follicles on our faces. These usually harmless mites are found in higher numbers on the skin of people with rosacea, the paper notes.

Rosacea is often treated with antibiotics, the paper explains, despite the fact that no bacterial cause of the condition has yet been identified. Perhaps, the paper reasons, the bacteria in these mites’ bellies might be the culprit; that would explain why antibiotics often keep rosacea in check.

The connection’s not been fully established yet, the authors note, but evidence suggests that when these mites die, their bodies may shed bacteria on the skin, where they leak molecules that trigger an immune response. That reaction may signal the start of rosacea, the paper notes; from there, a vicious cycle may ensue wherein mites and bacteria make bigger inroads where skin is inflamed or damaged.

The paper’s authors note that their work may point the way toward more effective treatments for an annoying, sometimes disfiguring condition.