Background: The atopy varies in people of different ages owing to different physical conditions and allergens exposure.  

Objective: We aimed to cluster ages based on atopic severity using K-means cluster analysis and identify atopic incidence, severity as well as the characteristics of poly-sensitization of various allergens based on the age categories

Methods: Consecutive patients (n=7654) with allergic symptoms and undergoing allergen-specific IgE tests were included from 2013 to 2017.

Results: Five age categories were identified: 1?17, 18?36, 37?52, 53?69 and 70??100 years. The incidences and severity of atopy decreased with increasing age, as well as the proportion of poly-sensitization. Dust mites accounted for the most common allergens and had higher sensitive indexes in all age groups. Besides, egg and milk seemed to attack children and adolescents more often. Elderly patients had higher incidence and severity of seafood sensitization In patients aged <52 years, sensitization to aeroallergens was more prevalent than food allergens.

Conclusion: Distinct demographic features such as age are associated with atopy. In our large-scale cohort study, the incidence and severity of most allergen sensitizations decreased with increasing age, as well as poly-sensitization, based on age grouping using K-means cluster analysis. This age stratification method helps to find the changes in atopic status and distribution of sensitized allergens with age more properly, and it will make the research on atopy more accurate and valuable.