Abstract
Background The consumption of plant-based food has lately largely increased, raising concerns about allergic reactions from ingredients which are currently not subject to mandatory labelling.Methods We analysed the frequency and severity of allergic reactions to non-mandatory labelled allergenic foods (pea, lentil, bean, chickpea, fenugreek, pine nut, sunflower-, poppy-, pumpkin seed, buckwheat) from two large European cohorts: The Anaphylaxis Registry (NORA) and EuroPrevall outpatient clinic study. Severity was assessed using the Food Allergy Severity Score (FASS) and compared with reactions to mandatory labelled allergenic foods.Results Among 589 reactions from both cohorts, sunflower seed was the most frequent trigger (n = 126). In NORA, pine nut (1.0% of food-induced allergic reactions) was most common followed by pea and buckwheat (0.7% each); in EuroPrevall, sunflower seed (1.2%), poppy seed (0.6%) and lentil (0.6%) predominated. After adjusting for age and sex, the severity of reactions to mandatory labelled seeds and legumes (excluding peanut) were not different (nFASS median: 4.39 vs. 4.43 and 4.56 vs. 4.49). Whereas, cereal-induced reactions (6.47) were significantly more severe than buckwheat (4.77). In Nora, the number of reactions to fenugreek and pumpkin seed were 7.4- and 3.7-fold higher in 2015-2022 versus 2007-2014.Conclusion Non-mandatory labelled allergenic foods were identified to cause severe allergic reactions in two large European cohorts. The frequent involvement of sunflower seed, pine nut, pea and lentil, but also rising numbers of reactions to fenugreek and pumpkin seed, indicates their potential risk. These allergenic foods warrant close monitoring and consideration in future allergen labelling revisions.