Alison YM Lee, Paul Enarson, Ann E Clarke, Sébastien La Vieille, Harley Eisman, Edmond S Chan, Christopher Mill, Lawrence Joseph, Moshe Ben-Shoshan

There are no data on the percentage of visits due to anaphylaxis in the emergency department (ED), triggers, and management of anaphylaxis across different provinces in Canada. To compare the percentage of anaphylaxis cases among all ED visits, as well as the triggers and management of anaphylaxis between two Canadian pediatric EDs (PEDs). As part of the Cross-Canada Anaphylaxis Registry (C-CARE), children presenting to the British Columbia Children's Hospital (BCCH) and Montreal Children's Hospital (MCH) EDs with anaphylaxis were recruited. Characteristics, triggers, and management of anaphylaxis were documented using a standardized data entry form. Differences in demographics, triggers, and management were determined by comparing the difference of proportions and 95% confidence interval. Between June 2014 and June 2016, there were 346 visits due to anaphylaxis among 93,730 PED visits at the BCCH ED and 631 anaphylaxis visits among 164,669 pediatric visits at the MCH ED. In both centers, the majority of cases were triggered by food (BCCH 91.3% [88.7, 94.0], MCH 82.4% [79.7, 85.3]), of which peanuts were the most common culprit (24.7% [20.9, 29.9] and 19.0% [15.8, 22.7], respectively). Pre-hospital administration of epinephrine (BCCH 27.7% [23.2, 32.8], MCH 33.1% [29.5, 37.0]) and antihistamines (BCCH 50.6% [45.2, 56.0], MCH 47.1% [43.1, 51.0]) was similar. In-hospital management differed in terms of increased epinephrine, antihistamine, and steroid use at the BCCH (59.2% [53.9, 64.4], 59.8% [54.4, 65.0], and 60.1% [54.7, 65.3], respectively) compared to the MCH (42.2% [38.3, 46.2], 36.2% [32.5, 40.1], and 11.9% [9.5, 14.8], respectively). Despite differences in management, percentage of cases admitted to the intensive care unit was similar between the two centers. Compared to previous European and North American reports, there is a high percentage of anaphylaxis cases in two PEDs across Canada with substantial differences in hospital management practices. It is crucial to develop training programs that aim to increase epinephrine use in anaphylaxis.