The 2017 Addendum Guidelines for the Prevention of Peanut Allergy were associated with lower new-onset anaphylaxis rates in children, according to a study published in The Journal of Allergy and Clinical Immunology: In Practice. “Food allergies, especially to peanuts, have been on the rise,” Joshua Yu, MD, internal medicine resident, department of medicine, faculty of medicine, McMaster University, and first author of the study, told Healio.
“Early introduction of peanuts to infants has shown promise in preventing peanut allergies at least within randomized controlled trials,” Yu said. “In 2017, Canada introduced new guidelines encouraging early introduction. However, it was unclear how these guidelines affected the rates of peanut-induced severe allergic reactions (anaphylaxis) in Canada.”
Methods
The retrospective study analyzed data from a longitudinal registry of anaphylaxis presentations at the ED at Montreal Children’s Hospital between May 2011 and December 2019. Patients were divided into groups based on prior known peanut allergies and then further stratified into two age groups: 0 to 2 years and 3 to 17 years. The former age range was chosen since those patients had the opportunity to participate in early peanut introduction from 2017 to 2019, unlike the latter age group. Rates of peanut-induced anaphylaxis were calculated by presentations per 100,000 age-adjusted all-cause ED visits in 4-month intervals. To compare anaphylaxis rate trends before and after 2017, an interrupted time series analysis was used.
Results
Among 2,011 cases of pediatric anaphylaxis, 429 (21%) were peanut-induced, including 180 (mean age, 4.11 years; 58% boys) with no known prior peanut allergy and 249 (mean age, 9.13 years; 63% boys) with a known prior peanut allergy at ED presentation. Prevalence of baseline asthma was significantly lower in the younger subgroup, with a significantly higher prevalence of baseline eczema. Within the known peanut allergy in this subgroup, 11 patients had no history of prior anaphylaxis but had a history of eczema and egg allergy, and of these patients, four presented with anaphylaxis following 2017.
Analysis showed a significant yearly –7.96 (95% CI, –14.57 to –1.36) slope change in anaphylaxis rates after 2017 in the 109 children in the 0 to 2 years age group without prior known peanut allergy. “In young children ages 0 to 2 without known prior allergy to peanuts, we found a significant decrease in the rate of peanut-induced anaphylaxis presentation rates to the Montreal Children’s Hospital ED after the introduction of the 2017 guidelines,” Yu said. “In contrast, there was no significant change in rates in children aged 3 to 17 years or in patients with known peanut allergies of any age group.”
Yu explained that these findings provide real-world evidence that early peanut introduction is associated with reduction in incidence of peanut-induced anaphylaxis in young children.“This supports the efficacy of early allergen introduction as a preventive measure,” he said. “The lack of significant changes in older children and those with known allergies underscores the importance of early intervention. It suggests that the window for preventing peanut allergies may be limited to early childhood.” He further stated that physicians should focus their efforts on educating new parents and caregivers about the benefits that early introduction of allergens can bring and that further studies need to be done in order to fully assess the benefits. “Future research should investigate the long-term effects of early peanut introduction across Canada and explore its impact on other food allergens,” Yu said. “Studies on guideline adherence and demographic influences on anaphylaxis rates are also needed.”