Impact of climate change on aerobiology, rhinitis, and allergen immunotherapy: Work Group Report from the Aerobiology, Rhinitis, Rhinosinusitis & Ocular Allergy, and Immunotherapy, Allergen Standardization & Allergy Diagnostics Committees of the American Academy of Allergy, Asthma & Immunology.

Climate change is imposing a profound effect on health conditions triggered by environmental exposures. Climate change has affected aeroallergens in numerous ways, including: (1) changes in the vegetation microbiome distribution, (2) increases in C4 grasses globally, (3) increased occurrence of acute weather events, (4) increases in ambient temperature that amplify fungal spore concentration and pollen season duration, and (5) increased allergenicity of pollen and fungi due to exposure to higher levels of carbon dioxide, ozone, and diesel exhaust particles. In addition, greenhouse gases and air pollutants disrupt the epithelial barrier, trigger eosinophilic inflammation, and serve as adjuvants that stimulate IgE-mediated responses. All of these factors have influenced the prevalence and morbidity of allergic rhinitis, nonallergic rhinitis, and chronic rhinosinusitis. Data regarding changes in aeroallergen exposures due to climate change are lacking, and longitudinal sensitization data are rarely available. Allergists need to adapt diagnostic and treatment strategies to limit aeroallergen and air pollutant exposure and facilitate desensitization. Steps needed to address these challenges include: (1) expanding local measurement of pollen and fungal spores, (2) increasing the intensity of allergen avoidance measures, (3) addressing supply chain issues, and (4) promoting collaboration between allergists, insurance companies, aeroallergen manufacturers, and regulatory agencies.