Rosacea Epidemiological Investigation and Etiology Exploration in the Plateau Area.

Background: The epidemiology of 2 neighboring cities of differing altitude in Northwest China is unknown. The present study investigated the prevalence of rosacea in a high-altitude city and a low-altitude city.

Methods: The prevalence study was conducted via clinical examination of male and female participants in the following age groups: 5-17, 18-30, 31-50, and 51-70 years. Rosacea subtype was also determined as erythematotelangiectatic rosacea (ETTR) or papulopustular rosacea (PPR).

Results: The rosacea prevalence (RP) in the low-altitude city was 33.8% ± 1.2% (95% CI, ETTR = 1794, PPR = 174, n = 5794). RP in the high-altitude city has a notably higher reading of 47.7% ± 1.4% (95% CI, ETTR = 2090, PPR = 219, n = 4796). In both cities, the ETTR subtype predominated, and there was marked increase in RP among females. RP in low-altitude city females was steady across all age groups, while RP in low-altitude city males showed a declining trend with age. RP in high-altitude city females indicated a slightly increasing trend with age, while RP in males again showed a declining trend with age. Based on the results of this high-altitude city and low-altitude city study, there are an estimated 2.1 million people with rosacea, from 2 cities with a total population of 5.4 million.

Conclusions: Due to the high altitude and accompanying increased UV radiation, cold climate, and reduced oxygen density, the greater northwest region of China is expected to experience high RP rates.