Etiopathogenesis of rosacea: a prospective study with a three-year follow-up.

BACKGROUND: The aim of this study was to investigate the role of Demodex folliculorum (DF), Helicobacter pylori (HP), and small intestine bacterial overgrowth (SIBO) in the development of rosacea.

METHODS: A case-control study including 60 patients with rosacea and 40 healthy controls was performed. All the patients underwent standardized skin surface biopsy to investigate DF, urea breath test for HP and lactulose breath test and glucose breath test for SIBO. Etiological therapy was started in the following order: acaricidal treatment, antibiotics for SIBO and HP. These exams were repeated after 3 years. Statistical analysis was performed.

RESULTS: As regards the 88 patients who completed the entire follow-up, DF positivity was found in 47.7% of the patients, SIBO in 25.0%, and HP in 21.6%. SIBO significantly prevailed in papulopustular rosacea, while HP in erythrosis. At the 6-month follow up, the 61% of patients were in remission. After 3 years, 18% of patients dropped out, while the remaining patients repeated all the investigations. The majority of patients were still in remission and negative for HP while only 5 were positive for DF and 4 for SIBO.

CONCLUSIONS: SIBO was the most relevant factor in papulopustular rosacea. Its treatment was crucial in improvement and in maintaining the clinical remission.