A newly-revised European Academy of Allergy and Clinical Immunology (EAACI) food allergy guideline provides both a document assisting healthcare professionals in IgE-mediated food allergy diagnosis and updates on clinical management of such food allergies.¹

The research which led to the new guideline was led by Alexandra F. Santos, MD, MSc, from the Department of Women and Children's Health (Pediatric Allergy) at the School of Life Course Sciences in King's College London.

“There are other causes of adverse reactions to foods that do not have an immunologic mechanism and need to be considered as part of differential diagnosis of IgE-mediated food allergy,” Santos and colleagues wrote. “Such clinical entities may be metabolic, pharmacologic or toxic in origin or have a different underlying mechanism.”

This new guideline by the EAACI was formulated by both building upon iteration 2014 guidelines and upon the guidelines on immunotherapy for patients with IgE-mediated allergies that had been released in 2018.^2,3

Background and Findings

The EAACI’s food allergy guideline mainly addressed IgE-mediated food allergies, and was intended for specialists in allergy as well as generalists workin with suspected food allergies. A steering committee led by Santos oversaw the new guideline's creation.

An expert group’s contributions were provided to ensure relevance around the world, with the group including authors of current EAACI section members, prior EAACI Food Allergy Guidelines, experts from around the world, nurses, psychologists, junior members, and patient representatives from the European Federation of Allergy and Airways Diseases (EFA) and the EAACI Patient Organisations' Committee (POC).

The team’s new guideline's diagnostic module was based upon both systematic literature reviews by the team and meta-analyses. When evidence was lacking, the investigators used expert consensus and recommendations that were formulated using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) method.

The guideline’s group of experts periodically looked over the results and would then carry out electronic voting, a process which required a minimum of 80% approval for the team’s recommendations to be acceptable.

The research team notes that diagnosis of patients’ food allergies begins with a detailed clinical history focusing on the patients’ allergies. This check up is then followed up with tests to assess their IgE sensitization—including serum allergen-specific IgE (sIgE) and a skin prick test (SPT)—along with the basophil activation test (BAT) if it is shown to be available.

The team further emphasized the importance of seeking out evidence of IgE sensitization for any potential allergens to food. They added that SPT and serum sIgE can work decently for certain types of food such as cashews or peanuts, these tests are known to be less reliable for other types such as soy and wheat.

To enhance healthcare professionals’ diagnosis of patients, the measurement of sIgE to specific allergen elements like Cor a 14 (hazelnut), Ara h 2 (peanut), and Ana o 3 (cashew) can be useful, with the team acknowledging the unique helpfulness for subjects known to have pollen sensitivities.

The research team also noted that BAT can be utilized for both peanut and sesame, adding that the highest standard for diagnosis of allergies to food is the oral food challenge (OFC) and that it should be considered by professionals in equivocal cases. They reported that open challenges are known to be practical for most types of cases.

Additionally, the team stated that periodic reassessment of food-allergic patients who are children with allergy tests and/or OFCs may at some point lead to reintroduction of foods if oral tolerance is shown to spontaneously develop in these individuals.

“The current Guideline intends to provide guidance for best clinical practice and refer to specific studies included in the systematic review of the literature and meta-analyses that informed the guidelines,” they wrote. “However, the quality and design of the included studies needs to be carefully reflected upon when considering extrapolating study findings, namely cut-offs and measures of diagnostic accuracy, to one's own clinical practice.”

References

1. ^{Santos, AF, Riggioni, C, Agache, I, et al. EAACI guidelines on the diagnosis of IgE-mediated food allergy. Allergy. 2023; 00: 1-20. doi:10.1111/all.15902.}
2. ^{Pajno GB, Fernandez-Rivas M, Arasi S, et al. EAACI guidelines on allergen immunotherapy: IgE-mediated food allergy. Allergy. 2018; 73(4): 799-815. doi:10.1111/all.13319.}
3. ^{Muraro A, Werfel T, Hoffmann-Sommergruber K, et al. EAACI food allergy and anaphylaxis guidelines: diagnosis and management of food allergy. Allergy. 2014; 69(8): 1008-1025. doi:10.1111/all.12429.}