Rosacea is associated with chronic systemic diseases in a skin severity-dependent manner: Results of a case-control study A portion of this work was presented at the Society for Investigative Dermatology Annual Meeting in Albuquerque, New Mexico, May 7-10, 2014.

Background Rosacea is a common chronic inflammatory dermatosis of unclear origin. It has been associated with systemic comorbidities, but methodical studies addressing this association are lacking. Objective We evaluated: (1) the association between rosacea and systemic comorbidities; and (2) if the severity of rosacea is impacted by comorbidities. Methods This was a case-control study: patients with rosacea were matched (1:1) to rosacea-free control subjects by age, sex, and race. Relative risk estimates were calculated using logistic regression as odds ratios with 95% confidence intervals. Results Among 130 participants (65 patients/65 control subjects), we observed a significant association between rosacea and allergies (airborne, food), respiratory diseases, gastroesophageal reflux disease, other gastrointestinal diseases, hypertension, metabolic and urogenital diseases, and female hormone imbalance. Compared with mild rosacea, moderate to severe rosacea was significantly associated with hyperlipidemia, hypertension, metabolic diseases, cardiovascular diseases, and gastroesophageal reflux disease. Limitations This was a case-control study with moderate sample size. Associated medical conditions were self-reported and could not always be confirmed by medication use and medical records. Conclusions Rosacea is associated with numerous systemic comorbid diseases in a skin severity-dependent manner. Physicians should be aware of these associations to provide comprehensive care to patients with rosacea, especially to those with more severe disease.