Sensitization Characteristics of Allergens in Children in Hangzhou from 2021 to 2025

A retrospective cross-sectional study was conducted by including the results of serum allergen sIgE quantitative tests performed on patients at Hangzhou First People's Hospital from January 1, 2021, to December 31, 2025. The trends in sIgE positivity rates across different years, as well as the characteristics of age and monthly distributions, were analyzed. The Chi-square (χ²) test was used for comparisons between groups.

Results: A total of 50931 sIgE test results were included in the study, comprising 29634 males (58.2%) and 21,297 females (41.8%). The positivity rate for total IgE was 59.7%. The top five allergens with the highest overall positivity rates were Dermatophagoides pteronyssinus (41.3%), milk (19.6%), dog dander (8.8%), cat dander (7.8%), and mixed grasses (5.4%).

In the infant group, the primary sensitizing allergen was egg white (11.1%), followed by milk (9.9%) and shrimp/crab (8.2%). In the toddler group, milk was the leading allergen (17.1%), followed by Dermatophagoides pteronyssinus (16.6%) and egg white (11.7%). For the preschool group, Dermatophagoides pteronyssinus ranked first (37.2%), followed by milk (20.8%) and dog dander (8.5%).

In both the school-age and adolescent groups, Dermatophagoides pteronyssinus was the most prevalent allergen (50.7% in both groups), followed by milk (19.4%) and cat dander (10.6% in school-age; 11.9% in adolescents). The sensitization rates for Dermatophagoides pteronyssinus, cat dander, and mold mix showed an increasing trend with age. Conversely, sensitization to egg white and shrimp/crab exhibited a gradual decline after the age of 3.

Seasonal peaks in sIgE positivity were observed for specific inhalant allergens: Dermatophagoides pteronyssinus peaked in July (49.6%) and August (52.6%); cat dander peaked from August (9.4%) to October (9.1%); dog dander peaked from July (10.9%) to October (10.0%); tree pollen mix peaked from June (4.1%) to August (4.3%); and mold mix peaked from May (4.4%) to August (4.1%). Conclusion: The trends in allergen sIgE among patients at Hangzhou First People's Hospital from 2021 to 2025 reflect the characteristics of allergic diseases in children in Shangcheng District, Hangzhou, to a certain extent.

While the positivity rate of total IgE showed no significant trend over the years, the top three allergens with the highest overall positivity rates were Dermatophagoides pteronyssinus, milk, and dog/cat dander. The sIgE sensitization patterns varied significantly across different age groups, and the distribution of inhalant allergen sIgE positivity rates also differed by month. In clinical practice, allergen test reports should be interpreted comprehensively, taking into account factors such as patient history, age, and the month of the clinical visit.