To evaluate the clearing and intensity of symptoms of rosacea 60 days after the treatment of Helicobacter pylori infection.Design: Randomized, double-blind, placebo-controlled clinical trial. Setting:The dermatology section of a large multispecialty clinic in the North Central United States.Participants: Men and women older than 25 years with active signs of rosacea who tested positive for H pylori with both the rapid whole blood test and the urea breath test.Intervention: Treatment of H pylori infection with 14day therapy using clarithromycin, 500 mg orally 3 times a day, and omeprazole, 40 mg orally once a day. Main Outcome Variables:The extent and intensity of rosacea as measured by the number of papules and pus-tules and the extent and intensity of erythema and telangiectasia.Results: Three hundred twenty patients presented with rosacea. For 50 patients, the results of a urea breath test were positive for H pylori, and 44 patients were enrolled in the study. Rosacea abated in almost all patients, but none were cured. Notably, lessening of rosacea for patients treated for H pylori was not significantly better than for the control cohort.