Utility of food allergy thresholds.

Food allergy is a prevalent disease worldwide that is a significant quality-of-life burden, and accidental exposures to food allergens may elicit severe, life-threatening reactions such as anaphylaxis. The threshold level, or the dose that triggers an allergic reaction determined by oral food challenges, varies considerably among individuals suffering from food allergies. Moreover, IgE concentration, diversity, or function can only partially explain this variation in threshold; pathogenic effector TH2 cells have also been found to contribute to the eliciting dose. Though very sensitive to cofactors such as physical activity/stress, the threshold is a stable and reproducible feature of an individual's allergy over periods of many months, made clear in the past several years from treatment studies in which repeated threshold determination has been used as a treatment outcome; however, there also seem to be age-related changes at a population level. More routine determination of food allergy thresholds may help patients stratify risk to improve the management of their food allergy. Precautionary allergen labeling, such as "may contain" labels, often causes confusion since they are inconsistent and regularly contain little to trace allergen residues; thus, food products with such labeling may be unnecessarily avoided. Population-based eliciting dose levels have been determined in the literature; patients at lower risk with higher thresholds may be more confident with introducing foods with precautionary allergen labels. Understanding a patient's threshold level could aid in shared decision-making to determine the most suitable treatment options for patients, including the starting dose for oral immunotherapy and/or the use of biologics.

Food aversion and poor weight gain in food protein-induced enterocolitis syndrome: A retrospective study.

BACKGROUND: Food protein-induced enterocolitis syndrome (FPIES) is a form of non-IgE-mediated gastrointestinal food allergy. Insufficient data exist in regard to gastrointestinal history and outcome, particularly comorbidity, family history, food aversion, and poor body weight gain. OBJECTIVE: We sought to identify the gastrointestinal outcomes and related risk factors in FPIES. METHODS: We analyzed the clinical features and gastrointestinal outcomes of patients with FPIES retrospectively at 4 hospitals in Boston. RESULTS: Two hundred three patients with FPIES were identified, including 180 only with acute FPIES, 8 with chronic FPIES, and 15 with both. Oat (34.5%), rice (29.6%), and cow's milk (19.2%) were the most common food triggers. The prevalence rates of personal history with allergic proctocolitis (23.2%) and family history with inflammatory bowel diseases (9.4%) and celiac disease (7.3%) were higher than those in the general population. Compared with patients with FPIES with 1 or 2 food triggers, the risk of developing food aversion increased in cases triggered by 3 or more foods (adjusted odds ratio, 3.07; 95% CI, 1.38-6.82; P = .006). The risk of poor body weight gain increased in FPIES triggered by cow's milk (adjusted odds ratio, 3.41; 95% CI, 1.21-9.63; P = .02) and banana (adjusted odds ratio, 7.63; 95% CI, 2.10-27.80; P = .002). CONCLUSIONS: Gastrointestinal comorbidities and family history were common in patients with FPIES. Patients with FPIES with 3 or more triggers were at risk of food aversion. Patients with FPIES with cow's milk and banana as triggers were at risk of poor body weight gain.