The Impact of Early-Life, Long-Term Exposure to Ambient Particulate Matter on Atopic Dermatitis Remission and Sensitization in Infants.

BACKGROUND: Studies that examine a link between long-term exposure to ambient particulate matter (PM) and atopic dermatitis (AD) in children are lacking. This longitudinal study aimed to investigate the effect of long-term exposure to PM on AD in infants. METHODS: We enrolled 150 infants aged 0-1 years with AD and followed them until age 3 in Seoul, Korea. We assessed long-term exposures to ambient particulate matter with an aerodiameter < 10 µm (PM₁₀) from birth to age 3 using a fusion model based on each individual's home address. Effects of long-term exposure to PM₁₀ on AD persistence and sensitization to aeroallergens were evaluated using Cox proportional hazard regression models after adjusting for potential confounders. RESULTS: Of the 150 infants, 54 (36.0%) showed remission of AD by age 3. Overall, long-term exposure to PM₁₀ was not significantly associated with AD persistence at age 3 (hazard ratio [HR], 1.04; 95% confidence interval [CI], 0.97-1.12; P = 0.267 per 1 µg/m³). However, when stratified by the baseline AD severity, increased exposure to PM₁₀ significantly elevated the risk of persistence in children with moderate AD at enrollment (HR, 1.19; 95% CI, 1.05-1.36; P = 0.007). Long-term exposure to PM₁₀ was also associated with an increased overall risk of sensitization to pollen (HR, 1.12; 95% CI, 1.00-1.24; P = 0.043), with a more pronounced effect in children with moderate AD (HR, 1.31; 95% CI, 1.08-1.58; P = 0.005). However, no significant association was observed between PM₁₀ exposure and sensitization to house dust mite or pet allergens. CONCLUSION: An early-life long-term exposure to ambient PM₁₀ in infants with AD may decrease the remission and increase the sensitization to pollen at age 3.