[Analysis of sensitization characteristics and changing trends of common allergens in a children's hospital in Shanghai City from 2020 to 2024].

Objective: To explore the clinical distribution characteristics and changes of common inhalant allergens and food allergens in all outpatient and inpatient children visiting Shanghai Children's Hospital from 2020 to 2024, and to provide a basis for the diagnosis, treatment and prevention of allergic diseases in children. Methods: A retrospective cohort study was conducted to retrospectively enroll all outpatient and inpatient children who visited Shanghai Children's Hospital and underwent serum allergen-specific IgE (sIgE) antibody testing from January 2020 to August 2024, and the characteristics and changing trends of allergens in the past 5 years were analyzed. A total of 127 310 tests were included. There were 76 776 male tests (60.31%) and 50 534 female tests (39.69%). There were 27 392 tests (21.52%) aged 0-3 years (infant group), 51 596 tests (40.53%) aged 4-6 years (preschool group), 44 574 tests (35.01%) aged 7-12 years (school-age group), and 3 748 tests (2.94%) aged 13-18 years (adolescent group). The χ2 test was used for statistical analysis. Results: The difference in total positivity rate between different years was statistically significant (χ2=2 907.478, P<0.001). The positive rates of inhalant allergens such as house dust, Dermatophagoides pteronyssinus/Dermatophagoides farinae, cockroach, cat dander, mugwort, Humulus scandens, mold fungi mix, and food allergens such as beef and mutton increased significantly with age (The χ2 values were 649.496, 3 414.686, 303.247, 1 277.408, 40.477, 189.952, 600.737, 203.198, and 15.301, respectively, and the P values were <0.001, <0.001, <0.001, <0.001, <0.001, <0.001,<0.001,<0.001, and 0.002, respectively). The positive rates of inhalant allergen such as Ambrosia elatior (1.59%) and food allergens such as egg white (17.36%), milk (30.48%), shrimp (8.27%), crab (8.13%), codfish (2.61%), salmon (0.66%), mytilus edulis (2.89%), lobster/scallop (5.27%), cashew nuts (5.09%), peanuts (3.54%), and soybean (1.73%) were highest at the age of 0-3 years and decreased significantly with age (The χ2 values were 10.365, 2 407.443, 139.085, 872.548, 870.245, 106.823, 47.674, 47.244, 559.422, 369.800, 384.788, 153.660, respectively, and the P values were 0.016, 0.000,<0.001,<0.001,<0.001,<0.001,<0.001,<0.001,<0.001,<0.001,<0.001,<0.001, respectively). Inhaled allergens mainly have a greater impact on children with respiratory-related diseases such as allergic rhinitis and asthma, while food allergens mainly have a greater impact on children with atopic dermatitis/eczema. The positive rate of sIgE of various allergens in the allergic rhinitis combined asthma group were higher than that of allergic rhinitis alone, and the sIgE positive rate of total allergens and inhaled allergens was significantly higher than that of allergic rhinitis alone (χ2=20.851, 39.155, the P values were both<0.001). Among them, the sIgE positive rate of Ambrosia elatior and cashew nuts showed significant difference (χ2=5.044, 8.420, P=0.025, 0.004); and the sIgE positive rate of Dermatophagoides pteronyssinus/Dermatophagoides farinae, cat dander, grass pollens mix and mold fungi mix had extremely significant difference (χ2=26.409, 25.990, 21.283, 16.411, the P values were all <0.001). The inhaled allergens and food allergens with the highest positive rates in the 5 years were Dermatophagoides pteronyssinus/Dermatophagoides farinae (56.21%) and milk (47.47%), and as time went by, the positive rates gradually decreased. There is a moderate correlation between the three allergens of Ambrosia elatior, Amaranthus retroflexus, and tree pollens mix (0.55, 0.70, 0.63), and there is a moderate correlation between mango and tree pollens mix (0.50). Conclusion: Dermatophagoides pteronyssinus/Dermatophagoides farinae, cat dander, dog dander, egg white, and milk may be important allergens for children in Shanghai City from 2020 to 2024. The positive rates vary among different genders, age groups, and disease groups, but the positive rates of Dermatophagoides pteronyssinus/Dermatophagoides farinae, milk and cat dander allergens remain in the top three.