Evaluation of Prehospital Management in a Canadian Emergency Department Anaphylaxis Cohort

J Allergy Clin Immunol Pract. 2019 Sep-Oct;7(7):2232-2238.e3. doi: 10.1016/j.jaip.2019.04.018. Epub 2019 Apr 26.


Background: Studies assessing the use of antihistamines and corticosteroids for the treatment of anaphylaxis have not supported a conclusive effect.

Objective: To assess prehospital management of anaphylaxis by measuring the effect of epinephrine use compared with antihistamines and corticosteroids on negative outcomes of anaphylaxis (intensive care unit/hospital ward admission, multiple doses of epinephrine in the emergency department [ED], and intravenous fluids given in the ED).

Methods: The Cross-Canada Anaphylaxis Registry is a cohort study that enrolls anaphylaxis cases presenting to EDs in 5 Canadian provinces over a 6-year period. Participants were recruited prospectively and retrospectively and were excluded if the case did not meet the definition of anaphylaxis.

Results: A total of 3498 cases of anaphylaxis, of which 80.3% were children, presented to 9 EDs across Canada. Prehospital treatment with epinephrine was administered in 31% of cases, whereas antihistamines and corticosteroids were used in 46% and 2% of cases, respectively. Admission to the intensive care unit/hospital ward was associated with prehospital treatment with corticosteroids (adjusted odds ratio, 2.84; 95% confidence interval [CI], 1.55, 6.97) while adjusting for severity, treatment with epinephrine and antihistamines, asthma, sex, and age. Prehospital treatment with epinephrine (adjusted odds ratio, 0.23; 95% CI, 0.14, 0.38) and antihistamines (adjusted odds ratio, 0.61; 95% CI, 0.44, 0.85) decreased the likelihood of receiving multiple doses of epinephrine in the ED, while adjusting for severity, treatment with corticosteroids, asthma, sex, and age.

Conclusions: Prompt epinephrine treatment is crucial. Use of antihistamines in conjunction with epinephrine may reduce the risk of uncontrolled reactions (administration of 2 or more doses of epinephrine in the ED), although our findings do not support the use of corticosteroids.

Keywords: Anaphylaxis; Antihistamine; Corticosteroids; Epinephrine; Prehospital management.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Intravenous
  • Adolescent
  • Adrenal Cortex Hormones / therapeutic use*
  • Adult
  • Anaphylaxis / chemically induced
  • Anaphylaxis / etiology
  • Anaphylaxis / therapy*
  • Bronchodilator Agents / therapeutic use*
  • Canada
  • Child
  • Child, Preschool
  • Cohort Studies
  • Drug Hypersensitivity
  • Emergency Medical Services*
  • Emergency Service, Hospital
  • Epinephrine / therapeutic use*
  • Female
  • Fluid Therapy*
  • Food / adverse effects
  • Food Hypersensitivity
  • Histamine Antagonists / therapeutic use*
  • Hospitalization / statistics & numerical data*
  • Humans
  • Intensive Care Units / statistics & numerical data
  • Male
  • Registries
  • Severity of Illness Index
  • Venoms / adverse effects
  • Young Adult


  • Adrenal Cortex Hormones
  • Bronchodilator Agents
  • Histamine Antagonists
  • Venoms
  • Epinephrine