Introduction: Food allergy is increasing in prevalence and the severity of allergic reactions is unpredictable. Identifying food-allergic patients at high risk of severe reactions would allow us to offer a personalized and improved management for these patients.
Areas covered: We review the evidence for using the levels of specific IgE, the nature of the allergen, and cellular tests to identify patients at high risk of developing severe allergic reactions to foods.
Expert opinion: The evidence about whether the quantity of allergen-specific IgE reflects the severity of allergic reactions to foods is conflicting, with some positive and some negative studies. For some foods, specific IgE to individual components (e.g. Ara h 2 in peanut) can provide additional information. However, more important than the quantity of IgE is possibly the quality of IgE, which can be captured by individual measurements of affinity/avidity, diversity, and specific activity, but is best measured overall using the basophil and mast cell activation tests, which assess the function of IgE in its ability to induce cell activation, degranulation, and mediator release. Biomarkers look at a single aspect of the allergic response and should be interpreted in the broader clinical context for each individual patient assessed.
Keywords: Food allergy; IgE; anaphylaxis; basophil activation test; mast cell activation test; peanut allergy; severity; skin prick test.