Air pollution and global healthcare use for atopic dermatitis: A systematic review

Associations of ambient air pollution and daily outpatient visits for pediatric atopic dermatitis in Shanghai, China

Limited evidence was available on ambient air pollution and pediatric atopic dermatitis (AD). The study aimed to evaluate the associations between short-term exposure to air pollutants and outpatient visits for pediatric AD. From 2016-2018, we collected data on six criteria air pollutants (PM2.5, PM10, NO2, SO2, CO and O3) and daily outpatient visits for pediatric AD in 66 hospitals, covering all districts in Shanghai, China. The over-dispersed Poisson generalized additive model (GAM) was applied to fit the associations of criteria air pollutants with hospital visits. Two-pollutant models were fitted and stratified analyses by sex, age and season were conducted. We identified 477,833 outpatient visits for pediatric AD. Each interquartile range (IQR) increase in PM2.5 (IQR: 30.9 μg/m3), PM10 (8.9 μg/m3), NO2 (25.5 μg/m3), SO2 (5.8 μg/m3) and CO (0.283 mg/m3) on the concurrent day was significantly associated with increments of 2.08 % (95 % CI: 0.53 %, 3.65 %), 2.53 % (95 % CI: 0.87 %, 4.22 %), 8.14 % (95 % CI: 6.24 %, 10.08 %), 5.67 % (95 % CI: 3.58 %, 7.80 %), and 2.27 % (95 % CI: 0.70 %, 3.87 %) in pediatric AD outpatient visits, respectively. The effects of NO2 remained robust after adjustment for other air pollutants. The exposure-response curves for PM2.5 and PM10 were steeper for moderate-lower concentrations, with a flatten curves at high concentration; nearly linear relationships were found for NO2. Higher associations of NO2 exposure on AD were detected in children under 6 years old (p=0.01); and we observed larger effect of air pollutants in cool seasons (p<0.001 for PM2.5, PM10, NO2 and CO; p=0.043 for SO2). This study indicated that short-term exposure to air pollution could increase risk of outpatient visits for pediatric AD.

National prevalence of atopic dermatitis in Korean adolescents from 2009 to 2022

Previous studies have examined the prevalence of allergic diseases in adolescents 1-2 years after the emergence of the COVID-19 pandemic. However, more data is needed to understand the long-term impact of COVID-19 on allergic diseases. Thus, we aimed to examine the trend of the atopic dermatitis prevalence in Korean adolescents before and during the COVID-19 pandemic across 14 years. Additionally, we analyze the risk factors of atopic dermatitis (AD) based on the results. The Korean Disease Control and Prevention Agency conducted the Korea Youth Risk Behavior Web-based Survey from 2009 to 2022, from which the data for this study were obtained. Prevalence trends were compared across subgroups, and the β difference (βdiff) was calculated. We computed odds ratios to examine changes in the disease prevalence before and during the pandemic. This study included a total of 917,461 participants from 2009 to 2022. The prevalence of atopic dermatitis increased from 6.79% (95% CI 6.66-6.91) in 2009-2011 to 6.89% (95% CI 6.72-7.05) in 2018-2019, then decreased slightly to 5.82% (95% CI 5.60-6.04) in 2022. Across the 14 years, middle school student status, low parent's highest education level, low household income, non-alcohol consumption, non-smoker smoking status, no suicidal thoughts, and no suicide attempts were associated with increased risk of atopic dermatitis, while female sex, rural residence, high BMI, low school performance, low household income, and no feelings of sadness and despair was associated with a small increase. This study examined the prevalence of atopic dermatitis across an 18-year, and found that the prevalence increased in the pre-pandemic then decreased during the start of the pandemic and remained constant throughout the pandemic. This trend could be explained mainly by the large scale social and political changes that occurred during the COVID-19 pandemic.

Effects and mechanisms of polycyclic aromatic hydrocarbons in inflammatory skin diseases

Polycyclic aromatic hydrocarbons (PAHs) are hydrocarbons characterized by the presence of multiple benzene rings. They are ubiquitously found in the natural environment, especially in environmental pollutants, including atmospheric particulate matter, cigarette smoke, barbecue smoke, among others. PAHs can influence human health through several mechanisms, including the aryl hydrocarbon receptor (AhR) pathway, oxidative stress pathway, and epigenetic pathway. In recent years, the impact of PAHs on inflammatory skin diseases has garnered significant attention, yet many of their underlying mechanisms remain poorly understood. We conducted a comprehensive review of articles focusing on the link between PAHs and several inflammatory skin diseases, including psoriasis, atopic dermatitis, lupus erythematosus, and acne. This review summarizes the effects and mechanisms of PAHs in these diseases and discusses the prospects and potential therapeutic implications of PAHs for inflammatory skin diseases.

Association of air quality index (AQI) with incidence of atopic dermatitis in Taiwan: A nationwide population-based cohort study

BACKGROUND

Air pollutants may aggravate atopic dermatitis (AD). However, the association between Air Quality Index (AQI) and incidence of AD remains unknown.

OBJECTIVE

To investigate association between AQI and incidence of AD, using the nationwide cohort in the Taiwan National Health Insurance Research Database (NHIRD).

METHODS

We included 21,278,938 participants from the NHIRD not diagnosed with AD before 2008. Long-term average AQI value, obtained from the Taiwan Air Quality Monitoring System Network, before AD diagnosis was calculated and linked for each participant.

RESULTS

199,205 incident cases of AD were identified from 2008 to 2018. Participants were classified into 4 quantiles (Q) by AQI value. With the lowest quantile, Q1, as reference, the AD risk increased significantly in the Q2 group (adjusted hazard ratio [aHR]: 1.29, 95% confidence interval [CI]: 1.04-1.65), Q3 group (aHR: 4.71, 95% CI: 3.78-6.04), and was highest in the Q4 group (aHR: 13.20, 95% CI: 10.86-16.60). As AQI treated as a continuous variable, an increase of 1 unit of AQI value added 7% of AD risk (aHR, 1.07, 95% CI: 1.07-1.08).

LIMITATIONS

The NHIRD lacks detailed information on individual subjects.

CONCLUSIONS

The results demonstrated a significant positive association between AQI and incidence of AD with a clear dose-response relationship.