Inclusion Criteria:  Patients < 18 years of age presenting to the ED with an allergic reaction that matches diagnostic criteria for anaphylaxis as defined by the World Allergy Organization (WAO) in 2019. The 2019 WAO anaphylaxis guidelines clarify the involvement of two organ systems to diagnose anaphylaxis, stating that "although the diagnosis of anaphylaxis usually depends on the involvement of multiple organ systems, anaphylaxis may present as an acute cardiac or respiratory event as the only manifestation of anaphylaxis." Thus, a patient with isolated hypotension, bronchospasm, or upper airway obstruction after exposure to a known or potential trigger will be deemed to have anaphylaxis, even if typical skin features are absent. Language proficiency in English or French  Exclusion Criteria:  Anaphylactic reaction that occurred in the context of a suicidal attempt or intoxication Anaphylactic reaction that begins in hospital and managed outside ED (on an inpatient or outpatient unit) Patient who is unable to complete the follow-up survey post ED discharge.