The impact of air pollution on allergic rhinitis

Recently, air pollution has become more and more severe globally and has decreased the quality of life significantly in subjects with or without allergic diseases. Air pollution more severely affects patients with allergic diseases, including allergic rhinitis (AR); therefore, it could devastate quality of life. Many epidemiological studies have shown that air pollutants increased outpatient clinic visits as well as the prevalence/severity of AR and decreased quality of life in patients with AR. Traffic-related air pollution also increases the severity and occurrence rate of AR, and heavy traffic is also associated with an increased prevalence of AR. Immunologically, air pollutants increase airway inflammation and mucin production by triggering the generation of reactive oxygen species and inducing the nucleotide-binding domain, leucine-rich repeat protein 3 inflammasome and apoptosis. Since air pollution affects both the upper and lower airways and is known to be a risk factor for AR, proper diagnosis and treatment should be applied. In this review article, we will address several epidemiological and clinical studies about the effects of air pollution on AR, mechanisms by which air pollutants aggravate AR, and treatment of AR triggered by air pollutant.