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Epidemiology of anaphylaxis and biphasic reaction in Japanese children
Kento Ikegawa1,2, Emi Morikawa2,3, Ayako Nigo1
1Department of General Pediatrics Tokyo Metropolitan Children's Medical Center Tokyo Japan.
Insights
Biphasic anaphylaxis reactions occur in 1.7% of pediatric cases, with clinically significant events in 0.3%. Careful monitoring of anaphylaxis patients is crucial due to the regular occurrence of these delayed reactions.
Area of Science:
- Pediatric Emergency Medicine
- Allergy and Immunology
- Clinical Epidemiology
Background:
- Anaphylaxis is a severe allergic reaction, but its epidemiology and biphasic reaction characteristics are not well-defined.
- Biphasic anaphylactic reactions in children range from 0.9% to 14.7%, with limited understanding of their specific features and observation duration.
Purpose of the Study:
- To investigate the epidemiology of anaphylaxis in children.
- To identify the characteristics of biphasic anaphylactic reactions in pediatric patients.
Main Methods:
- An observational study was conducted.
- Data were collected from pediatric emergency department (PED) admissions for anaphylaxis between March 2010 and March 2017.
Main Results:
- Out of 264,689 children visiting the PED, 353 (0.13%) were hospitalized for anaphylaxis.
- Six patients (1.7%) experienced biphasic reactions, with a median onset of 5.9 hours after initial symptoms.
- One patient (0.3%) had a clinically significant biphasic reaction requiring epinephrine.
Conclusions:
- The incidence of biphasic reactions was 1.7%, and clinically important biphasic reactions were 0.3%.
- Regular occurrence of biphasic reactions necessitates careful patient monitoring after anaphylaxis.
Aim:
Anaphylaxis is common, but can sometimes be fatal. However, data on the epidemiology and characteristics of anaphylaxis are limited. Although 0.9%-14.7% of anaphylactic reactions in children are biphasic, it is unclear what the characteristics of biphasic reaction are and how long patients with this reaction should be observed. The present study aimed to investigate the epidemiology of anaphylaxis and biphasic reactions and identify the characteristics of the latter.
Methods:
We conducted an observational study of patients who visited the pediatric emergency department (PED) and were hospitalized for anaphylaxis between March 2010 and March 2017.
Results:
Of the 264,689 children who visited our PED, 353 (1.3 per 1,000 patient) were hospitalized for anaphylaxis, and six (1.7%) had a biphasic reaction. Of the patients with a biphasic reaction, the median time from initial anaphylaxis to the biphasic reaction was 5.9 (interquartile range [IQR] = 3.3-7.6) hours. Symptoms of the initial episode and the biphasic reaction varied. One (0.3%) of the 353 patients developed a clinically important biphasic reaction that required epinephrine administration.
Conclusions:
The rate of biphasic reactions was 1.7%, and that of clinically important biphasic reactions was 0.3%. Patients with anaphylaxis need to be carefully monitored because of the regular occurrence of biphasic reactions.
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