Association Between Air Pollution and Psoriasis-Related Outcomes: A Systematic Review and Meta-analysis

Skin diseases are a group of consequences due to exposure to air pollution that have received less attention. Among these diseases, the relationships between short-term and long-term exposure to air pollutants and psoriasis remain uncertain. The present systematic review and meta-analysis aimed to investigate association between exposure to various air pollutants and psoriasis incidence. A comprehensive literature search was conducted in three valid databases. Two researchers independently screened articles for eligibility. Subsequently, data were systematically extracted from the final eligible articles. The quality of the studies was evaluated utilizing the Joanna Briggs Institute (JBI) critical appraisal instruments. Moreover, a meta-analysis was performed. 23 of 25 reviewed studies showed that various air pollutants can significantly affect psoriasis-related outcomes, including true incident psoriasis and Flare-related/healthcare utilization. The pooled risk ratios related to relationships between nitrogen dioxide, nitrogen oxides, ozone, sulfur dioxide, PM 2.5 , and PM 10.0 and psoriasis incidence per 10 µg/m³ increase in each pollutant concentration were 1.092 (95% CI 1.062–1.123); P < 0.001], 1.126 (95% CI 1.046–1.213); P = 0.002], 1.012 (95% CI 1.002–1.021); P = 0.019], 1.044 (95% CI 1.023– 1.065); P < 0.001], 1.089 (95% CI 1.066–1.112); P < 0.001], and 1.079 (95% CI 1.052–1.107); P < 0.001], respectively. The pooled risk ratios were greater for annual exposure duration, long-term exposure, and prolonged psoriasis duration. It is suggested that exposure to these pollutants is controlled, especially in people susceptible to psoriasis.