Association of Meteorological Factors and Air Pollutants With Atopic Dermatitis in Children: A Systematic Review and Meta-Analysis

Abstract

There is no consensus on the impact of meteorological factors and air pollutants on childhood atopic dermatitis (AD). Literature was searched in 3 databases (PubMed, Web of Science, and Embase) up to May 1, 2025, and evaluated by 2 independent reviewers. Cross-sectional studies, cohort studies, or time-series analyses were included, reporting outcomes of meteorological factors, air pollutants, and childhood AD. The Newcastle–Ottawa Scale and Agency for Healthcare Research and Quality scale were used to assess study quality. A random-effects model was applied to estimate pooled risk ratios. From 132 identified literature, 49 studies involving nearly 7,091,746 participants were included. Air pollutants were positively correlated with the risk of childhood AD (odds ratio [OR] [95% confidence interval or CI] = 1.030 [1.005, 1.056] for carbon monoxide [CO]; 1.116 [1.075, 1.264] for nitrogen dioxide [NO₂]; 1.059 [1.013, 1.108] for ozone; 1.114 [1.039, 1.260] for particulate matter [PM] with diameter of 10 µm [PM₁₀]; 1.041 [1.009, 1.074] for PM with diameter of 2.5 µm [PM_2.5]). No clear associations were observed between sulfur dioxide, temperature, humidity, and ultraviolet radiation (UVR) and the risk of childhood AD. Subgroup analysis showed that higher temperature and UVR might reduce the risk of AD, increased concentrations of CO, NO₂ in developed countries, and PM₁₀, PM_2.5, and NO₂ might increase the incidence risk in developing countries. Air pollutants represented significant risk factors for childhood AD, underscoring the imperative to prioritize environmental quality improvement for AD prevention.