Allergic disease affects up to 40% of the global adult population, a proportion that is increasing with environmental changes related to global warming. We undertook a systematic review of the literature to identify and evaluate the current evidence of the impact of climate change-related environmental factors on the allergen production and the epidemiology and severity of allergic pathologies. PECO criteria were established and guided the literature searches of the PubMed and Cochrane databases (Jan 1, 2016 to Dec 31, 2021). Study outcomes were categorized and grouped to facilitate data synthesis. Outcomes were classified as significant (statistical significance <0.05), non-significant (p>0.05) or undetermined (p value not reported). Study quality was assessed using MMAT analysis. Of 195 studies, 40 were considered relevant and 9 of them provided data to be included in the data quantitative synthesis. Environmental factors, including the presence of pollutants, temperature, and drought, influenced the type, volume, and timing of exposure to local aeroallergens. The most relevant environmental factor was the presence of environmental pollutants, of which tropospheric ozone was the most frequently associated to changes in allergen production, prevalence, and severity of allergic disease. Also, several publications demonstrated the impact of environmental factors on the healthcare burden. Climate-change related environmental factors increased allergic disease in terms of prevalence, severity, and healthcare burden due to alterations in allergen exposure (volume and type) with the presence of pollutants such as ozone being the most commonly reported driver of such increase.