Intestinal flora may play a role in causing the disease. A recent study subjected patients to a hydrogen breath test to detect the occurrence of small intestinal bacterial overgrowth (SIBO). It was found that significantly more patients were hydrogen-positive than controls indicating the presence of intestinal flora overgrowth (47% v. 5%, p<0.001).
Hydrogen-positive patients were then given a 10-day course of rifaximin, a non-absorbable antibiotic that does not leave the digestive tract and therefore does not enter the circulation or reach the skin. 96% of patients experienced a complete remission of rosacea symptoms that lasted beyond 9 months.
These patients were also negative when retested for intestinal flora overgrowth. In the 4% of patients that experienced relapse, it was found that intestinal flora overgrowth had returned.
These patients were given a second course of rifaximin which again cleared rosacea symptoms and normalized hydrogen excretion.