389 Association between short-term exposure to environmental air pollution and atopic dermatitis flare under treatment with dupilumab

The magnitude of the short/medium-term air pollution exposure on atopic dermatitis (AD) flare has not been fully investigated. The aim of the study is to investigate the association of short/medium-term exposure to airborne pollution on AD flares in patients treated with dupilumab. This is an observational case-crossover study. Patients with moderate-to-severe AD under treatment with dupilumab were included. The exposure of interest was the mean concentrations of coarse and fine particulate matter (PM10,PM2.5), nitrogen dioxide and oxides (NO2,NOx). Different intervals were considered at 1-60 days prior to AD flare and control visit, defined as the visit with the highest and EASI≤7, respectively. A conditional logistic regression analysis adjusted for systemic treatments was employed to estimate the incremental risks (IR%) of flare every 10 μg/m3 pollutants concentration. Data on 169 out of 528 AD patients with 1130 follow-up visits and 5840 air pollutant concentrations measurements were retrieved. The mean age was 41.4±20.3 years; 94(55%) men. The IR% curve indicated a significant positive trend of AD flare for all pollutants in all time windows. At 60 days, every 10 μg/m3 PM10,PM2.5,NOx and NO2 increase concentration was associated with 82%,67%,28% and 113% risk of flare, respectively. In conclusion, in patients treated with dupilumab, acute air pollution exposure is associated with an increased risk for AD flare with a dose-response relationship.