Pediatric Anaphylaxis Model Flags Need for Repeat Epinephrine

Key Takeaways

• Among 2,318 children who received one epinephrine dose before ED arrival for an allergic reaction, 15.7% received epinephrine again after arriving at the ED or during subsequent inpatient care.
• Seven prehospital factors were significantly associated with post-arrival epinephrine use, with asthma history and persistent, new, or recurrent symptoms after epinephrine standing out as clinically intuitive signals.
• With any risk factor present, the model showed high sensitivity and NPV for repeat epinephrine, while specificity and positive predictive value were lower.
• External validation still identified a 30.1% low-risk group, although 4.6% of those encounters received epinephrine after ED arrival.

After a child receives epinephrine for anaphylaxis before reaching the emergency department (ED), the immediate disposition question is whether improvement is durable enough for observation outside the hospital or whether residual risk still warrants ED evaluation. Under the 2023 U.S. Anaphylaxis Practice Parameter, some community-treated patients may not require ED care, although the source notes this was a conditional recommendation based on very low-certainty evidence, but persistent or recurrent symptoms can quickly narrow that decision for clinicians and families. Prehospital features that remain or recur after treatment may help estimate which children are more likely to need additional care after arrival, a question Dribin and colleagues examined in a large pediatric cohort.

Dribin and colleagues in The Journal of Allergy and Clinical Immunology: In Practice reported a 31-center retrospective cohort study using 2016 to 2019 data from 2,318 children aged 6 months to younger than 18 years who had received one epinephrine dose for an allergic reaction before ED arrival. The primary modeled outcome was epinephrine receipt after ED arrival or during subsequent inpatient care. Most encounters were assigned to derivation (72.7%; n = 1,685), with 18% (n = 417) used for internal validation and 9.3% (n = 216) reserved for external validation; the overall median age was 8.4 years. The model drew only on prehospital information to estimate post-arrival risk.

Repeat epinephrine after ED arrival occurred in roughly one in six encounters. Seven prehospital factors were significantly associated with that outcome, including asthma history, cardiovascular symptoms before epinephrine, persistent symptoms after treatment, and new or recurrent respiratory, cardiovascular, gastrointestinal, or nonspecific symptoms afterward. Using the pediatric anaphylaxis risk model, any risk factor present yielded sensitivity 0.93, negative predictive value (NPV) 0.95, specificity 0.35, and positive predictive value (PPV) 0.25 for repeat epinephrine. In external validation, 30.1% of encounters were classified as low risk, 4.6% of those low-risk encounters still received epinephrine after ED arrival, and investigators said 28.7% (62/216) of encounters could potentially have been avoided; for clinically significant examination findings or high-acuity therapies after arrival, the same seven factors plus respiratory symptoms before epinephrine emerged, with external-validation sensitivity 0.97 and NPV 0.94 while specificity and PPV remained lower.

Dribin and colleagues interpreted the findings as reinforcing the 2023 U.S. Anaphylaxis Practice Parameter, particularly when persistent or new symptoms remain after epinephrine, while emphasizing that patients and caregivers should not be discouraged from seeking ED evaluation. They framed home-observation decisions as requiring broader clinical and practical judgment, including prior allergy history, reaction characteristics, asthma or other high-risk comorbidities, caregiver presence and comfort, access to a backup epinephrine device, EMS response time and proximity to emergency care, shared decision-making, and local protocols. They also noted that the cohort was limited to pediatric patients and that retrospective chart review may not capture prehospital predictor variables with complete accuracy.

The authors reported that this prehospital pediatric risk model showed strong rule-out performance for repeat epinephrine after ED arrival, but residual risk remained even among children categorized as low risk. They called for validation in other pediatric settings and in adults, along with prospective refinement of prehospital variables and eventual development of a more patient-specific risk-score calculator.

Clinician Questions

Which children with anaphylaxis were included in the prehospital epinephrine risk model?

The model applied to children aged 6 months to younger than 18 years who had already received one epinephrine dose for an allergic reaction before ED arrival across 31 centers, and the authors noted that validation is still needed beyond pediatric populations, including adults.

What counted as the broader post-arrival outcome beyond repeat epinephrine in pediatric anaphylaxis?

Investigators also assessed clinically significant examination findings or receipt of high-acuity therapies after ED arrival or during subsequent inpatient care, and for that broader endpoint the seven repeat-epinephrine factors plus respiratory symptoms before epinephrine emerged as the relevant prehospital predictors.

How did asthma history affect the pediatric anaphylaxis prediction model?

Asthma history was one of seven significant prehospital factors associated with epinephrine receipt after ED arrival. The investigators also performed a sensitivity analysis that incorporated asthma controller medication use as a surrogate marker of persistent asthma.