413 Wildfire-associated air pollution impacts clinic visits for itch and atopic dermatitis

Abstract

With climate change, the frequency and intensity of wildfires are expected to increase, leading to episodes of poor air quality that could exacerbate patients’ pre-existing dermatoses. To assess the effects of exposure to wildfire-associated air pollution on skin, we investigated if the 2018 California Camp Fire led to detectable increases in clinic visits for atopic dermatitis (AD) or itch at dermatology clinics 175 miles from the origin of the fire. We collected data from 2015-2019 on particulate matter (PM2.5) concentration and smoke plume density in San Francisco and the number of outpatient dermatology visits for AD or itch symptoms at an academic medical center. Data were analyzed using Poisson regression with empirical standard errors, and the models included exposure lags and covariates: patient age and sex, temperature, and humidity. We found that the rates of weekly pediatric AD clinic visits, adult AD clinic visits, and pediatric itch symptoms during the Camp Fire were respectively 1.75 (95% CI: 1.21, 2.50), 1.28 (1.08, 1.51), and 2.10 (1.44, 3.00) times the rate for non-fire weeks for a 0-week lag, adjusted for time of year and confounders. Every 10 μg/m3 increase in average weekly PM2.5 concentration was associated with an adjusted rate ratio of 1.08 (95% CI: 1.04, 1.12) for weekly pediatric AD clinic visits. Thus, there was increased use of dermatology services for AD associated with exposure to air pollution from the Camp Fire, particularly for the pediatric population. With an impaired skin barrier function, AD patients may be at increased risk of adverse skin reactions following pollution exposure, which can negatively impact quality of life. Understanding the effects of air pollution on patients’ skin health can inform how dermatologists counsel patients and expand comprehension of the broader health effects of climate change.