Air Pollution Linked to Increased Psoriasis Burden: Meta-Analysis

Key Takeaways

• Pollutants PM_2.5, PM₁₀, and NO₂ showed the most consistent positive associations with psoriasis incidence in severity, and health care utilization, according to a new meta-analysis.
• Study data demonstrated small but measurable increases in psoriasis-related visits with NO₂ (2.3% increase) and PM_2.5 (0.32% increase).
• Subgroup analyses suggested variability by age and sex; stronger and more consistent associations were observed in adults and female populations.

New research presented at AAD 2026 suggests airborne pollutant particulate matter less than 2.5 microns in diameter (PM_2.5), PM₁₀, and NO₂ showed the most consistent positive associations with psoriasis incidence in severity, and health care utilization.

Investigators for the systematic review and meta-analysis focused on the association between outdoor air pollution exposure and psoriasis across epidemiologic studies and included data from 16 studies representing at least 995,300 participants and 573,241 medical visits. The analysis included multiple pollutants [PM_2.5, PM₁₀, nitrogen dioxide (NO₂), carbon monoxide (CO), sulfur dioxide (SO₂), and ozone (O₃)] and participants were stratified by age and sex.

The analysis results revealed that PM_2.5 showed a positive association with psoriasis outcomes in 11 of 14 analyses, aPM₁₀ showed positive associations in 6 of 10 studies, and NO2 in 9 of 9 studies. The authors reported the most consistent associations among adult populations and in female cohorts. Quantitative analysis showed small increases in psoriasis-related visits. NO₂ exposure was associated with a 2.3% increase in daily visits (95% CI, 1.3 to 3.4), while PM_2.5 exposure was associated with a 0.32% increase (95% CI, 0.19 to 0.48). 

Demographic factors, including age and sex, may modify risk, and that study heterogeneity, were cited as a key limitation. Contextual factors like baseline air quality and acute environmental events (eg, wildfires) were also factors potentially influencing associations.

“NO₂, PM_2.5, and PM₁₀ are the air pollutants with the strongest evidence for positive associations with psoriasis,” the authors wrote. “While the pooled associations for psoriasis may be small, baseline air quality and climate events…are important context to consider.”

Source: Fadadu R, MD, Jung A, Fernandez K, Wei M. Associations of Outdoor Air Pollution Exposure and Psoriasis: a Systematic Review and Meta-Analysis of Epidemiologic Evidence. Poster 71204. Presented at: 2026 American Academy of Dermatology Annual Meeting in Denver; March 27-31, 2026; Denver.