Study population
This was a multicenter study covering 44156 patients in 52 cities (from 26 provinces, 7 geographical regions) of mainland China from July 2015 to June 2018. The patients suffered from clinical symptoms of suspected allergic diseases, and serum allergen sIgE levels were detected. The suspected allergic diseases included allergic rhinitis (such as runny nose, sneezing, itching or nasal obstruction), skin allergy (such as rashes, wheal, eczema, or urticaria), and allergic asthma (such as wheezing, dyspnea, and/or cough not due to common cold). Patients with parasitic infections, immunodeficiency or under specific immunotherapy were excluded. The analyzed data covered the information on the medical diagnosis, demographic data, and sIgE levels for nine allergens. This study was approved by the ethics committee of the First Affiliated Hospital of Guangzhou Medical University (Approval number: GYFYY-2017-18).