Effects of Exposure to Indoor Fine Particulate Matter on Atopic Dermatitis in Children

This study aimed to investigate the short-term effect of exposure to indoor fine particulate matter (PM ) on atopic dermatitis (AD) symptoms in children. Sixty-four children (40 boys and 24 girls) with moderate-to-severe AD, aged under 18 years were enrolled in the study. They were followed up from February 2019 through November 2020. Exposure to indoor PM in each household of the enrolled children and their AD symptoms were measured daily. The generalized linear mixed model was utilized for statistical analysis. Subdivision analysis was performed by stratifying the patients by age, sex, season, severity, the presence of family allergic diseases, sensitization, and indoor environment conditions including temperature and relative humidity. A total of 9,321 person-days of AD symptom data were collected. The average PM concentration was 28.7 ± 24.3 µg/m , with the highest value in winter (47.1 ± 29.6 µg/m ). The overall effect of PM on AD symptoms was not statistically significant. However, an increase of 10 µg/m in indoor PM concentration increased AD symptom scores by 16.5% (95% CI: 6.5, 27.5) in spring and12.6% (95% CI: 4.3, 21.5) in winter, 6.7% (95% CI: 2.3, 11.3) at indoor temperatures of