No abstract

Background: Peanut, tree nut, and sesame allergies are responsible for most life-threatening food-induced allergic reactions. Rates of coexistent allergy between these foods have been from mostly retrospective studies that include only a limited number of tree nuts or were not based on oral food challenges. Objective: The Pronuts study is a multicenter European study (London, Geneva, and Valencia) assessing the challenge-proven rate of coexistent peanut, tree nut, and/or sesame seed allergy. Methods: Children aged 0 to 16 years with at least 1 confirmed nut or sesame seed allergy underwent sequential diagnostic food challenges to all other nuts and sesame seed. Results: Overall, the rate of coexistent peanut, tree nut, and sesame seed allergy was 60.7% (n 5 74/122; 95% CI, 51.4% to 69.4%). Peanut allergy was more common in London, cashew and pistachio nut allergies were more common in Geneva, and walnut and pecan allergies were more common in Valencia. Strong correlations were found between cashew-pistachio, walnut-pecan, and walnut-pecan-hazelnut-macadamia clusters. Age (>36 months) and center (Valencia > Geneva > London) were associated with an increased odds of multiple nut allergies. By pursuing the diagnostic protocol to demonstrate tolerance to other nuts, participants were able to introduce a median of 9 nuts. Conclusion: We found a higher rate of coexistent nut and sesame seed allergies than previously reported. Performing sequential food challenges was labor intensive and could result in severe allergic reactions; however, it reduced dietary restrictions. Age was a significant predictor of multiple nut allergies, and thus the secondary spread of nut allergies occurred in older children.

What is already known about this topic? The introduction of nuts and seeds in the diet of children with 1 or more nut allergies is safe and feasible; however, because of polysensitization, this often requires multiple oral food challenges (OFCs).What does this article add to our knowledge? The basophil activation test (BAT), when used after skin prick and specific IgE testing, can reduce the number of OFCs, particularly positive OFCs, maintaining very high diagnostic accuracy.How does this study impact current management guidelines? In children with 1 or more nut allergies, needing an OFC to clarify the allergic status to other nuts, a positive BAT confirms allergy, whereas a negative BAT requires an OFC before recommending nut consumption or avoidance. BACKGROUND: Nut allergic patients are often IgE sensitized to other nuts/seeds and need multiple oral food challenges (OFCs) before the safe nuts can be introduced in the diet. However, OFCs are time-consuming and risky procedures.OBJECTIVE: To assess the utility of the basophil activation test (BAT) to predict the allergic status and reduce the need for an OFC in children with 1 or more nut or seed allergies. METHODS: Participants in the Pronuts study recruited at the Geneva and the London centers were tested on

No abstract