Clinical thresholds to egg, hazelnut, milk and peanut: results from a single-center study using standardized challenges

Abstract Background Large studies of individual thresholds and risk profiles for foods are sparse. Previous reports indicate that thresholds adjusted for the protein content in foods would be comparable. Objective To establish and compare clinical threshold values for egg, hazelnut, milk and peanut, and correlating them to severity of symptoms. Methods Seven hundred eighty-one challenges were performed in 487 patients (age range, 0.5–73.5 years). Using interval censoring survival analysis, the dose distribution of thresholds was fitted to a log-normal function. Symptom score was correlated to thresholds. Results Based on the 405 challenges resulting in objective signs, similar distribution of thresholds for hazelnut, milk, and peanut challenges were found, whereas individuals with egg allergy were bimodally distributed with a high or a low threshold. Eliciting dose in 10% (95% confidence interval) was 42.9 (24-76.8) mg whole eggs, 133.8 (95.9–186.6) mg whole hazelnut, 106.5 (59.7–190.6) mg roasted peanut, and 2.9 (1.5–5.4) mL milk. Adults showed more severe symptoms and signs than children, and peanut caused more severe reactions than the 3 other foods. Conclusion Thresholds for the different foods were not comparable, and eliciting dose for the 4 foods differed, even if adjusted for protein content. Increasing age but not a low threshold dose is associated with severe symptoms on challenge. Peanuts elicit more severe reactions than the other foods.