Hospital-based patterns of allergen sensitization among 19,787 patients with suspected allergic diseases in Ningbo, China

Background: Allergic diseases encompass a range of disorders driven by hypersensitive immune responses to environmental allergens, with increasing global prevalence linked to environmental and lifestyle changes. Given regional variations in allergen sensitization patterns, localized epidemiological data are needed to inform clinical management. Methods: This single-center, hospital-based retrospective study included 19,787 patients with suspected allergic diseases who underwent serum specific IgE (sIgE) testing between January 1, 2019 and December 31, 2021 at the First Hospital Affiliated with Ningbo University in Ningbo, China. Diagnoses were made according to standard clinical criteria, and repeated tests from the same individual were excluded. Sensitization to 15 common inhalant and food allergens was quantitatively assessed using a standardized immunoblot assay (Dixun Biological Genetic Engineering Co., Ltd., China), with sIgE ≥0.35 kU/L defined as positive. We described overall sensitization rates and examined variations across calendar years, sex, age groups, and clinical disease categories. Results: Dust mites were the most common sensitizing allergens (37.0%), followed by milk (14.3%) and mixed grasses (6.4%). Sensitization rates for several major allergens varied significantly by year. Male patients showed higher sensitization rates to multiple allergens than females. Age-stratified analysis revealed a shift from predominant food allergen sensitization (e.g., milk, egg white) in early childhood to inhalant allergen sensitization (e.g., house dust mites, mixed grasses) in adolescence and adulthood. Sensitization patterns also differed significantly across clinical disease entities, with distinct profiles observed in patients with allergic rhinitis, asthma, and atopic dermatitis. Conclusion: This large hospital-based study delineates the allergen sensitization profile among patients with suspected allergic diseases in Ningbo, eastern China. These findings underscore the importance of considering age, sex, year of testing, and disease type when interpreting sIgE results in clinical practice. Because sIgE positivity reflects sensitization rather than confirmed clinical allergy, our results should be interpreted as sensitization patterns in a symptomatic, selected population rather than as prevalence estimates in the general population. Nonetheless, establishing a regionally relevant allergen sensitization spectrum may help optimize diagnostic panels, inform targeted prevention strategies, and support precision management of allergic diseases in this region.