The relationship between short-term PM 2.5 exposure and outpatient visits for acne vulgaris in Chongqing, China: a time-series study.

Many researches have reported the air pollution impacts, either long term or short term, on inflammatory skin diseases, but there are few studies on the relation between PM 2.5 and acne vulgaris. To determine the correlation between short-term PM 2.5 exposure and acne outpatient visits, data for 120,842 acne vulgaris outpatient visits between December 2013 and December 2019 were obtained from three large hospitals in Chongqing, China. Both single-pollutant models and two-pollutant models were established to explore the relationship between PM 2.5 exposure and acne outpatient visits. The stratified analyses were conducted through two-sample z-tests to investigate the possible gender (male or female) and age (< 25 years or ≥ 25 years) differences in PM 2.5 effects. The results demonstrated positive correlations between PM 2.5 concentrations and acne outpatient visits. A 10 μg/m 3 increase in PM 2.5 concentration was associated with a 1.71% (95% CI: 1.06-2.36%) increase in acne outpatient visits at lag 0-7 day. Stratified analyses showed that PM 2.5 effects were greater in individuals aged ≥ 25 years than those aged < 25 years, but no gender difference was found. In conclusion, short-term PM 2.5 exposure was positively associated with the risk of acne outpatient visits, especially for people ≥ 25 years old.