Study Underscores the Need to Unify Anaphylaxis Severity Scoring Systems

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New research highlighted the need to improve anaphylaxis scoring systems and to circulate unified diagnostic criteria for anaphylactic reactions.1

“Today, depending on the used classification, it is impossible to simply state the grade of severity of an anaphylactic reaction without contextualizing it to the referred scoring method,” wrote investigators, led by Yanis Bouderbala, from the allergy unit at Hôpital Arnaud de Villeneuve, University Hospital of Montpellier, in France. “Our work underlines, therefore, the importance of disseminating and using a simple and unified global classification to improve education, clinical approaches to patients, and clear interactions between physicians.

Anaphylaxis has a clear definition: “a serious systemic hypersensitivity reaction that is usually rapid in onset and may cause death.”2 The World Allergy Organization (WAO) anaphylaxis committee proposed that the anaphylaxis diagnosis should be based on 1 of 2 criteria:

1. The acute onset of an illness with the involvement of the skin or mucosal tissue and associated with a respiratory compromise, reduced blood pressure, or severe gastrointestinal symptoms.
2. An acute onset of hypotension or bronchospasm, or laryngeal involvement, in an individual with a previous allergy and suspected exposure to this allergen.

Although anaphylaxis has a well-defined diagnostic criterion, there is still debate on classifying the severity of an anaphylactic reaction. Several classifications emerged in recent years, such as the 11th version of the International Classification of Diseases (ICD‐11), the CoFAR, Dribin, EAACI (European Academy of Allergy and Clinical Immunology), and Blazowski.1

These classifications have significantly advanced anaphylaxis management, such as recommending the early use of adrenaline. However, the lack of uniformity in grading anaphylaxis severity across different classifications can lead to inconsistencies in how allergies are treated for potentially life-threatening reactions. These differences in proposed classifications consider allergic triggers, age groups, and whether the reaction occurred in a real-life exposure or a hospital iatrogenic setting.

In this recent retrospective observational monocentric study, investigators sought to evaluate possible discrepancies in the scoring system for anaphylaxis, looking at various classifications. Secondary objectives included comparing symptoms before and after a positive food challenge and assessing the effectiveness of an adrenaline injection based on the severity of symptoms; to see if adrenaline was an appropriate management, the team compared patients who did and did not experience anaphylaxis during the challenge.

The team assessed the scoring system among 235 adults and children who underwent a positive oral food challenge for an IgE-mediated food allergy between January 2018 – December 2022. Patients with a history of anaphylaxis had a prescription for Adrenaline Auto-Injector, and parents or caregivers had to bring an emergency kit with the adrenaline the day of the oral food challenge.

According to the ICD-11 classification, more than half of the sample (60.9%) suffered from anaphylaxis. Participants experiencing anaphylaxis experienced significantly more respiratory and gastrointestinal symptoms. The analysis also found that less than half of participants suffering from anaphylaxis (47.6%) received an adrenaline injection, including in a specialized setting.

“What still needs to be the cornerstone of the management of anaphylaxis is the injection of IM adrenaline, and the diagnosis of anaphylaxis should remain essentially based on a clinical assessment of the patient,” investigators wrote. “If, on one hand, the injection of adrenaline should never be delayed, regardless of the supposed severity of the anaphylactic reaction, an easy and practical overall accepted classification could help avoid the underuse of adrenaline.”

When comparing the different classifications, investigators found a complete concordance in only 8 patients (5.6%). All 5 classifications showed a good sensitivity (99.3% - 100%) but a wide-ranging specificity (67.4% - 93.5%). The study observed discrepancies in the different classifications of most patients.

“We showed that the likelihood of agreement between the different classifications is low, especially if we consider that they are based on 3–5 different grades: such discrepancy shows that the multitude of classifications doesn't help understand the severity of the reaction,” investigators wrote. “…from an educational point of view, and for a better management between teams and an easier comprehension from non‐specialized physicians…the use of an easy‐to‐understand simple and common classification would help reduce possible misunderstandings and improve the therapeutic approach towards patients.”

References

1. Bouderbala Y, Clark E, Tanno LK, Demoly P, Caimmi D. Anaphylaxis severity grade, during oral food challenges, assessed by five different classifications. Pediatr Allergy Immunol. 2025 Mar;36(3):e70065. doi: 10.1111/pai.70065. PMID: 40116239; PMCID: PMC11926947.

2. Cardona V, Ansotegui IJ, Ebisawa M, El-Gamal Y, Fernandez Rivas M, Fineman S, Geller M, Gonzalez-Estrada A, Greenberger PA, Sanchez Borges M, Senna G, Sheikh A, Tanno LK, Thong BY, Turner PJ, Worm M. World allergy organization anaphylaxis guidance 2020. World Allergy Organ J. 2020 Oct 30;13(10):100472. doi: 10.1016/j.waojou.2020.100472. PMID: 33204386; PMCID: PMC7607509.