The purpose of this study is to determine the effects of rifaximin on skin symptoms in patients with rosacea by double-blinded, placebo-controlled, crossover study.

100 patients will be randomized into two groups.

Group A will receive one rifaximin 550 mg tablet three times a day (1650 mg/day) for 14 days, and after a 4-week washout period, receive one placebo tablet three times a day for 14 days.

Group B will receive placebo first, and then rifaximin with the same dosage schedule to Group A.

Assessments will be performed before application and 4 weeks after the last dosage, for both of rifaximin and placebo.

Inclusion Criteria:

• Males and females
• > 18 years of age with rosacea defined as:
• 3-40 papules/pustules and < 2 nodules,
• A score of 2-4 on the Investigator Global Assessment

Exclusion Criteria:

• Untreated pancreatic insufficiency
• Crohn's disease
• Ulcerative colitis
• Active celiac disease by clinical history
• End stage renal failure
• Less than 18 years old
• Pregnancy or positive pregnancy test
• Rosacea subtype 1 (no papules )
• Topical or oral antibiotics within 4 weeks
• Acne treatments within 4 weeks prior to randomization
• Systemic retinoids within 90 days
• Topical or systemic corticosteroids 4 weeks prior to randomization