D3.270 - Recent Trends in Food Allergy among Schoolchildren in a South Korean City (2018–2022)

Food allergy (FA) prevalence and triggers vary by region and time. However, long-term population-based data in major Asian metropolitan areas are limited. To investigate 5-year trends (2018–2022) in FA prevalence and causative allergens among schoolchildren in South Korea’s second-largest city.

This epidemiological study used repeated cross-sectional data from a population-based school survey conducted between 2018 and 2022, including students from all elementary, middle, high, and special schools (serving students with disabilities) in the study region. Food allergy was defined based on student self-report. Approximately 300,000 students were surveyed annually. Questionnaires were distributed to all students, and responses from students reporting food allergy were collected and analyzed. Annual overall and school-level prevalence of food allergy were calculated, and temporal changes in the distribution of reported causative foods were examined.

Overall FA prevalence rose significantly from 3.13% in 2018 to 4.50% in 2022, peaking at 4.88% in 2021 (P for trend < 0.001). Prevalence was consistently highest in elementary schools (peak 5.76%), followed by middle and high schools (P<0.001 for all). Students in special schools exhibited a relatively higher prevalence pattern across the study period. The distribution of causative foods changed over time, with some foods showing increasing reporting frequencies while others decreased. In elementary school students, traditional allergens such as peanut and egg remained prevalent, while a rapid increase in tree nut allergy—particularly walnut—represented the most notable temporal change over the 5-year period. In contrast, peach and seafood remained the predominant allergens among middle and high school students. Although allergen rankings were relatively stable in older students, the absolute number of cases for most allergens increased over time compared with 2018. Overall, age-related differences in the spectrum of causative foods were observed.

This large-scale survey reveals a significant rise in FA prevalence and a shifting allergen landscape among South Korean schoolchildren. The rising burden of tree nut allergies among younger children and the relatively high prevalence in special schools highlight the need for age-specific and environment-tailored management strategies for the prevention and management of food allergy in children and adolescents.