Comprehensive hospital-based regional survey of anaphylaxis in Japanese children: Time trends of triggers and adrenaline use

Background: Since few studies have analyzed time trends in pediatric anaphylaxis, including triggers and adrenaline usage, this study aimed to reveal these issues in a comprehensive analysis of pediatric anaphylaxis cases. Methods: The Aichi Medical Association performed a comprehensive survey of pediatric anaphylaxis cases aged under 15 years from 87 secondary and 25 tertiary emergency care hospitals in Aichi Prefecture (population 7.5 million), Japan. Results: Between April 2016 and March 2020, 3423 cases of anaphylaxis were identified. Food items were the most frequent trigger (73%), followed by exercise after food ingestion (4.3%), and drugs (2.2%). Egg (19%) and milk (17%) specifically were the most frequent among food triggers, while the largest proportional increase was observed in tree nuts from 6.0% in 2017 to 15% in 2019. Overall, 1647 (48%) cases were admitted to the hospital, of which 26 (0.8%) were admitted to the intensive care unit. Drug-induced anaphylaxis was associated with the highest admission rate (71%). Of the 2493 food-induced anaphylaxis cases, 1107 (44%) were treated with adrenaline. Among them, 343 cases included previously prescribed adrenaline auto-injectors (AAI), with 225 (66%) usages prior to hospital arrival. There was no significant difference in the admission rate between the cases in which AAIs were used and those with adrenaline administered in the hospital (68% and 72%, respectively). Conclusions: The proportion of tree nuts in food-induced anaphylaxis increased significantly. Although prehospital AAI use has become widespread, it was not associated with lower admission rate compared to in-hospital adrenaline usage. Copyright (C) 2021, Japanese Society of Allergology. Production and hosting by Elsevier B.V.

Automated summary

This study analyzed time trends, triggers, and adrenaline usage in pediatric anaphylaxis cases in Aichi Prefecture, Japan. It found that food was the most common trigger, with egg and milk being the most frequent, and a significant increase in tree nuts. The admission rate did not significantly differ between cases where adrenaline auto-injectors were used before hospital arrival and cases where adrenaline was administered in the hospital.