Rosacea is a common dermatological condition that is not fully understood. Doctors understand the basic mechanism that causes the symptoms (dilation of the blood vessels beneath the surface of the skin). They just don’t understand what triggers this reaction in the first place. There are several theories about causes. Some think a reaction to certain skin bacteria is to blame. Others believe the problem is more systemic – some kind of autoimmune malfunction due to overproduction of a peptide called cathelicidin. Oral antibiotics have long been used to reduce rosacea symptoms. However, it is the anti-inflammatory properties of these drugs rather than their antibacterial function that’s given credit for the improvement.

Bacterial Overgrowth Treatment Points to Systemic Problem

Now a different class of antibiotic (rifaximin) which is used to treat small intestinal bacteria overgrowth (SIBO) is being shown to have a positive effect in suppressing rosacea as well. What’s different about this drug is that it is local – it does not travel out of the gut into the blood stream. This fact is puzzling researchers. If the antibiotic isn’t traveling throughout the patient’s system, how is it having an effect on such a distant target as the skin?

Rosacea patients do tend to have a higher incidence of SIBO than the general population. Excessive amounts of this intestinal bacteria have also been tentatively linked to other chronic inflammatory conditions including scleroderma (hardening of the skin and connective tissue).

Of course, the presence of SIBO might just be another symptom that occurs in conjunction with these conditions rather than being an underlying cause. However, it’s pretty clear that there’s some connection between the intestines and the skin that is still not fully understood. At least getting rid of the SIBO appears to have a very beneficial result for patients with rosacea.  A whopping 96% of 113 patients in one small rifaximin study had significant improvement in their symptoms (78% had their lesions completely cleared). These results lasted for at least 9 months. That’s an impressive result for treating a condition that tends to flare up again so easily after most conventional treatments.