Small Intestinal Bacterial Overgrowth in Rosacea: Clinical Effectiveness of Its Eradication
Small Intestinal Bacterial Overgrowth in Rosacea: Clinical Effectiveness of Its Eradication
Abstract & Commentary
By Malcolm Robinson, MD, FACP, FACG, Emeritus Clinical Professor of Medicine, University of Oklahoma College of Medicine, Oklahoma City. Dr. Robinson reports no financial relationship to this field of study.
Synopsis: Rosacea patients have increased incidence of small bowel bacterial overgrowth vs controls, and the eradication of this overgrowth leads to almost complete and long-lasting skin lesion regression.
Source: Parodi A, et al. Clin Gastroenterol Hepatol. 2008;6:759-764.
Rosacea, a very common dermatosis, is characterized by chronic central facial and eyelid inflammation. G.I. disorders have been frequently noted in rosacea patients including flatulence, dyspepsia, altered bowel habits, and abdominal pain. Earlier publications describe association of rosacea with inflammatory bowel diseases, Helicobacter pylori, and other diagnoses. Various cutaneous rosacea lesions often improve with antibiotic therapy including agents such as metronidazole, macrolides, chloramphenicol, neomycin, and tetracyclines. Mechanism(s) for the efficacy of antibiotics remain unexplained. A few years ago, a study in the dermatology literature found that rosacea improved with reduction of GI transit time. The current authors decided to investigate possible involvement of small intestinal bacterial overgrowth (SIBO) in rosacea pathogenesis. Although they realized that the gold standard for SIBO would be a positive jejunal culture for > 105 organisms, they opted to use lactulose followed by glucose breath testing as validated surrogates. The study involved 114 consecutive rosacea patients (82 women and 32 men; 2 with flushing, 27 with erythrosis, and 84 with papulopustules) in an academic dermatology department along with 60 healthy age and sex matched controls. All patients had assessment of GI symptoms and their severity. Standard lactulose and glucose breath tests for methane and hydrogen were performed sequentially a week apart using a Quintron MicroLizer device. Helicobacter pylori, if present at baseline, was treated with triple therapy after the conclusion of the study, and these H. pylori positive individuals responded in the same way as those patients who had been negative for H. pylori. Breath testing was done at baseline, and patients with breath test-documented SIBO were randomized to receive rifaximin or placebo.
Rosacea patients had SIBO far more often than controls (52/113 vs 3/60, p < .001). Patients with papulopustules had SIBO more often than rosacea patients without such lesions (50/84 vs. 2/29, p < .001). Eradication of SIBO confirmed by breath testing was confirmed in 28 of 32 patients (87.5%), and these patients had significant reductions in reported gastrointestinal symptoms. Of the placebo recipients, 18 of 20 had unchanged rosacea, and 2/20 had worsened. Rifaximin recipients had complete clearance of rosacea in 20 of 28 patients (71.4%), and 6 patients had significant reduction in lesion severity. Only 2 patients had no benefit from treatment. Placebo recipients were subsequently treated with open label rifaximin, and eradication of SIBO could be accomplished in 45 of 52 patients (86.5%). Complete lesion eradication was achieved in 35 patients (78%) and improvement was noted in 8 patients (17.7%). Sixteen patients with no breath test evidence of SIBO were nonetheless empirically treated with rifaximin, and little clinical change was noted in rosacea lesions (partial improvement in 3 patients). Orocecal transit time was found to be significantly delayed in patients with SIBO. Clinical response to therapy was found to persist for at least 9 months after successful rifaximin therapy.
Commentary
This study seems to confirm a high prevalence of SIBO in rosacea along with an excellent response to therapy with the nonabsorbable antibiotic rifaximin. The precise pathogenesis underlying the relationship between SIBO and rosacea is still unclear, but it is hard to argue with the demonstration that there is such a relationship. As the authors themselves agree, the study could have been even more compelling had SIBO been documented using jejunal culture. However, the invasive nature of jejunal culture and other technical pitfalls make their choice of diagnostic approaches quite reasonable. There was no blinding in this study, and this is a great pity since blinding is always preferred. Nevertheless, the striking results seem hard to dispute. Although further confirmatory data from other centers will be helpful, the evaluation of rosacea patients for SIBO seems reasonable as does antibiotic treatment of those found to have evidence for such infections. Rifaximin seems to be a particularly good choice for the management of SIBO in view of its very poor systemic absorption and its lower predilection for development of bacterial resistance.
Rosacea patients have increased incidence of small bowel bacterial overgrowth vs controls, and the eradication of this overgrowth leads to almost complete and long-lasting skin lesion regression.Subscribe Now for Access
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