Rosacea may be caused by skin bacteria: study

Researchers from the National University of Ireland found that the mite species Demodex folliculorum, worm-like in shape lives inside the pilosebaceous unit which surrounds hair follicles of the face.

They are normal inhabitants of the face and increase in number with age and skin damage - for example, following exposure to sunlight.

The numbers of Demodex mites living in the skin of rosacea patients is higher than in normal individuals, suggesting a possible role for the mites in initiating the condition.

Rosacea causes reddening and inflammation of the skin mostly around the cheeks, nose and chin. In severe cases skin lesions may form and lead to disfigurement.

 

Researchers isolated the bacterium Bacillus oleronius from inside a Demodex mite and found it produced molecules provoking an immune reaction in rosacea patients.

This bacterium was also found to be sensitive to the antibiotics used to treat rosacea.

"The bacteria live in the digestive tracts of Demodex mites found on the face, in a mutually beneficial relationship. When the mites die, the bacteria are released and leak into surrounding skin tissues - triggering tissue degradation and inflammation," author Dr Kevin Kavanagh, said.

"Once the numbers of mites increase, so does the number of bacteria, making rosacea more likely to occur. Targeting these bacteria may be a useful way of treating and preventing this condition," Kavanagh said in a statement.

"Alternatively we could look at controlling the population of Demodex mites in the face.. Some pharmaceutical companies are already developing therapies to do this, which represents a novel way of preventing and reversing rosacea, which can be painful and embarrassing for many people," Kavanagh added.

The study was published in the Journal of Medical Microbiology.