Population-based incidence of food allergies in Olmsted County over 17 years

Background: There is growing concern about the rising incidence and prevalence of food allergy globally. We previously reported the incidence of food allergy in Olmsted County, Minnesota, between 2002 and 2011. We sought to update the incidence and temporal trends of food allergies in our region through 2018. Methods: By using the Rochester Epidemiology Project, all Olmsted County residents, with an incident diagnosis of food allergy between January 2, 2012, and December 31, 2018, were identified and their medical records were reviewed. These cases were combined with the previously collected incidence cases from January 2, 2002, and December 31, 2011, to understand longitudinal trends in food allergy incidence rates. Results: Over the 17-year study period, 1076 patients (58.0% male patients, 72.1% white) were diagnosed with an incident food allergy. The median (interquartile range) age at first diagnosis was 2.0 years (1.1-8.4 years). The overall annual incidence rate for all ages was 3.9 (95% confidence interval [CI], 3.6-4.1) per 10,000 person-years and was significantly higher in male than in female patients (4.4 [95% CI, 4.0-4.7] and 3.3 [95% CI, 3.0-3.6], respectively; p < 0.001). The most common food allergen was egg in infancy (57.7%), peanuts in ages 1-4 years (58.3%), tree nuts in ages 5-18 years (57.4%), and seafood in adults (≥19 years) (45.3%). Conclusion: The incidence of food allergy in Olmsted County steadily increased from 2002 to 2008, then remained relatively stable between the years 2008 and 2013, and again presented a rising trend over the next 5 years until 2018. This warrants further investigations into the effects of changes in guidelines for early introductions of allergenic foods and other factors that affect causality.