Trends in Asthma-Rhinitis Allergic Multimorbidity and Polysensitization in China: The CARRAD Study

The trends in allergic comorbidities secondary to the environmental variations in China remain unclear. We aimed to determine the variation of allergic comorbidities and polysensitization among asthma and/or rhinitis patients in the past decade. We assessed two nationally representative cross-sectional datasets from 2008 to 2009 and 2018 to 2019, which enrolled 2322 and 2353 patients, respectively. Over the present 10-year study period, the prevalence of allergic symptoms and allergen sensitivity among patients with multiple sensitivities in the 2018-2019 cohort was significantly higher than that in the 2008-2009 cohort, especially for mites, pollen, and animal allergens. The comorbidity rates of asthma, allergic rhinitis, conjunctivitis, and eczema were significantly increased in the 2018-2019 cohort. Also in that cohort, IgE polysensitization was significantly associated with the coexistence of asthma and rhinitis, and the number of IgE-reactive allergens was significantly associated with the number of multimorbidities. Use of an air-conditioner and carpet in the home, and keeping pet were linked to the risk of polysensitization. Our findings suggest an increase in the comorbidity rate and multimorbid polysensitized phenotype of allergic diseases in China. Asthma occurred in both cohorts more frequently with coexisting allergies than as a single entity.