Role of Small Intestinal Bacterial Overgrowth and Helicobacter pylori Infection in Chronic Spontaneous Urticaria: A Prospective Analysis

The aim of this study is to assess the associations between chronic spontaneous urticaria (CSU), Helicobacter pylori infection and small intestinal bacterial overgrowth. Forty-eight patients with CSU were studied by scoring the urticaria activity and assesing the quality of life. Patients with H. pylori infection (n=11) or small intestinal bacterial overgrowth (n=13) were specifically treated for one week and clinically evaluated both before and 4 weeks after the eradication therapy. Eradication of H. pylori infection led to a significant improvement in CSU (p<0.002). In contrast, eradication of small intestinal bacterial overgrowth was not associated with any clinical improvement in CSU, despite the fact that these patients had statistically significant more urticaria activity at baseline. Thus there is no evidence to support the eradication of small intestinal bacterial overgrowth in CSU, but eradication of H. pylori infection may result in an improvement of the disease.