Persistent, refractory, and biphasic anaphylaxis: a multidisciplinary Delphi study
Published: August 24, 2020
Anaphylaxis is a severe, systemic reaction that occurs after exposure to an allergy-causing substance such as foods, medications, or insect venom. During the past decade emergency department visits for anaphylaxis doubled among all ages and tripled among children. These reactions pose a significant emotional and financial burden on patients and families as well as the US healthcare system. Although most reactions resolve promptly after treatment with epinephrine, patients may experience persistent or recurrent symptoms necessitating additional interventions. However, there are no uniformly accepted consensus-based definitions to describe these disparate clinical outcomes, limiting researchers’ understanding of their epidemiology and risk factors as well as their ability to investigate or standardize their management.
In a recent study published in The Journal of Allergy and Clinical Immunology (JACI), a panel of 19 national and international experts in Emergency Medicine, Pediatrics and Allergy Immunology led by Dr. Timothy Dribin from Cincinnati Children’s Hospital developed consensus definitions of persistent, refractory, and biphasic reactions using Delphi methodology. The panel defined persistent anaphylaxis as a reaction fulfilling the National Institute of Allergy and Infectious Disease and Food Allergy and Anaphylaxis Network (NIAID/FAAN) diagnostic criteria and lasting at least four hours. Refractory anaphylaxis was defined by symptom-directed medical management (such as an intravenous fluid bolus for patients with hypotension), when the initial reaction required treatment with at least three doses of epinephrine. Biphasic anaphylaxis was defined as new/recurrent symptoms that fulfill NAID/FAAN criteria after complete initial symptom resolution without allergen re-exposure, and new/recurrent symptoms must occur within 1-48 hours from complete resolution of initial symptoms.
Successful validation, dissemination and application of these definitions will not only help standardize communication among clinicians and patients, but will also be foundational in defining and harmonizing outcomes in anaphylaxis research.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.
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