Unmasking the Impact of Air Pollution on Allergic Rhinitis.

Allergic rhinitis (AR) is a chronic, non-infectious inflammatory condition of the nasal mucosa, primarily mediated by immunoglobulin E (IgE). Over the past decades, there has been a steady rise in the prevalence of AR worldwide, underscoring its growing public-health relevance. While genetic predisposition plays a role in AR development, environmental factors, particularly air pollution, have emerged as critical contributors. This review comprehensively examines epidemiological evidence linking air pollutants—such as particulate matter, hazardous gases, traffic-related air pollution (TRAP), volatile organic compounds (VOCs), and environmental tobacco smoke (ETS)—to AR prevalence and severity. Furthermore, it explores the synergistic interactions between air pollutants and inhaled allergens, highlighting mechanisms through which air pollution exacerbates AR. These mechanisms include disruption of nasal epithelial barrier function, enhancement of IgE-mediated hypersensitivity, oxidative stress, amplification of inflammatory responses, epigenetic modifications, alterations in microbial communities, and neurogenic regulation. Despite significant advances, the complex interplay between air pollutants and AR is not yet fully delineated. Emerging fields such as epigenetics and microbiomics offer promising directions for future research. This review aims to deepen understanding of the impact of air pollution on AR, providing insights and foundations for improved prevention and management strategies.