Unveiling heterogeneity in individual thresholds

BACKGROUND: The prevalence of food allergies among children is on the rise, presenting with a spectrum of severity from mild cases to those resulting in anaphylaxis. Ensuring the safe progression of home-based food ingestion is essential in managing food allergy. While the oral food challenge (OFC) test ideally confirms the threshold and tolerated dose, past findings indicated that about 30% of children who passed peanut OFCs experienced peanut-related allergic reactions when introducing peanuts at home. OBJECTIVE: It is presumed that the immune reactions occurring within individual patients vary in levels according to the situation. To date, no reports have objectively examined these conditions. MATERIAL AND METHODS: We present the symptoms and validation of an objective biomarker in eight pediatric cases during home introduction of food allergens. The urinary Prostaglandin D metabolite (PGDM) was measured as a noninvasive biomarker. RESULTS: Some cases exhibited mild symptoms and elevated urinary PGDM levels during home introduction despite ingesting half the dose that confirmed as safe during OFC. CONCLUSION: It underscores the importance of considering individual variability in determining food allergy thresholds.