Scientific Study

Background: Food allergies, particularly peanut, represent the predominant cause of anaphylaxis. While early allergen introduction has emerged as a potential preventive strategy, the precise impact of recent guidelines on peanut-induced anaphylaxis rates in Canada remains unclear. Objective: To assess the impact of the 2017 Addendum Guidelines for the Prevention of Peanut Allergy on peanut-induced anaphylaxis rates in Canada. Methods: Using a comprehensive longitudinal registry capturing pediatric anaphylaxis presentations to the Montreal's Children's Hospital, we compared children with and without known peanut allergy who presented with peanut-induced anaphylaxis between 2011 and 2019 inclusive, excluding data beyond 2019 due to the COVID-19 pandemic. We calculated rates of peanut-induced anaphylaxis presentations per 100,000 age-adjusted all-cause Emergency Department visits using 4-month intervals. Interrupted time series analysis was used to compare anaphylaxis rate trends before and after 2017 for children ages 0-2 and 3-17 years. Results: We examined n = 2011 cases of pediatric anaphylaxis, including 429 (21%) triggered by peanuts. Compared to pre-guideline estimates, the yearly rate of change of peanut anaphylaxis rates decreased by 7.96 (95% CI -14.57 to -1.36, p = 0.018) after 2017 amongst patients with new onset anaphylaxis in children 2 years of age or younger (n = 109). No significant changes were identified for older patients ages 3-17, or in patients with known peanut allergy. Conclusion: Early introduction guidelines in Canada are associated with a reduced risk of new-onset peanut-induced anaphylaxis in young children within a single centre in Montreal. Further research is required to assess the impact on a wider population and other food allergens. https://doi.org/10.1016/j.jaip.2024.06.004