Milk-Induced Anaphylaxis Among Children Presenting to Canadian Emergency Departments

To describe the clinical presentation and management of pediatric patients with milk-induced anaphylaxis in Canadian emergency departments (EDs).This study included 3118 pediatric patients with anaphylaxis from 10 different Canadian EDs between April 2011 and May 2023.Patients were enrolled prospectively through interviews with families and retrospectively by chart review. The clinical courses of patients with anaphylaxis were recorded through a standardized form. The primary objectives were to determine risk factors for receiving 2 or more doses of epinephrine in the ED and to characterize the differences in reactions between patients < 5 years and those 5 years and older, when milk allergy may have resolved.Of the 3118 patients, 319 (10%) presented with milk-induced anaphylaxis. Of these patients, 171 (53.6%) received intramuscular epinephrine before ED arrival. Those with a known food allergy and those who received intramuscular epinephrine before ED arrival were less likely to require 2 or more epinephrine doses in the ED. Patients < 5 years were more likely to have a mild reaction (P = .005) and a faster onset of reaction (<5 minutes) (P = .003). Patients 5 years of age or older were more likely to have a moderate reaction (P = .0004) and a later onset of reaction (5 minutes to 2 hours) (P = .005). When compared with anaphylaxis from other food allergens, milk-induced anaphylaxis patients were younger (P < .001) and more commonly had symptoms of wheezing (P = .005) and vomiting. Epinephrine use in the ED and admission to the ICU was similar between milk-induced versus other food allergen anaphylaxis.Approximately half of patients with milk-induced anaphylaxis did not receive epinephrine before presenting to the ED. Prehospital administration of epinephrine was associated with a decreased risk of requiring 2 or more doses of epinephrine in the ED. This study also demonstrated patients 5 years and older were more likely to have a moderate reaction, suggesting those who do not outgrow their food allergy may experience worse reactions.This is the largest pediatric study on milk-induced anaphylaxis and highlights the importance of recognizing milk as a major cause of anaphylaxis in young children. This study also demonstrates continued underuse of epinephrine outside of the hospital. Further strategies to improve access and use of epinephrine autoinjectors in milk-induced anaphylaxis may decrease the severity and improve patient’s clinical course.