Climate change as a catalyst: rethinking allergen immunotherapy in a changing world

Climate change is reshaping the epidemiology and severity of allergic disease through mechanisms that extend beyond increased pollen exposure. Pollen seasons are lengthening, annual allergen loads are rising, and tropospheric ozone is chemically modifying pollen proteins in ways that enhance their allerginicity. The geographic expansion of allergenic plant species is generating new sensitization patterns in populations with no prior exposure history, and extreme meteorological events are precipitating acute asthma in individuals who previously had only rhinitis. In this evolving landscape, allergen immunotherapy (AIT), the only intervention capable of modifying the natural course of IgE-mediated allergic disease, becomes not less relevant, but more. Climate change strengthens the case for earlier and broader AIT prescription, calls for updated patient selection criteria and maintenance protocols, and demands investment in extract standardization. We argue that climate change is not merely a contextual backdrop for allergy practice but an active clinical variable that elevates the role of AIT as both an individual treatment and a population-level prevention strategy. A focused research agenda at the climate-immunotherapy interface is both timely and necessary, given a disease burden that is projected to grow.