Predicting outcomes of oral food challenges by using the allergen-specific IgE-total IgE ratio.

Background: Although allergists typically use allergen-specific IgE (sIgE) levels or skin prick test wheal sizes to identify food allergens that may provoke IgE-mediated food-induced allergic reactions, both tests have high rates of false positivity and mislabel patients who are tolerant as allergic to the food allergen.

Objective: To examine the accuracy of the ratio of sIgE to total IgE ("Ratio") in predicting the outcome of challenges performed to confirm the development of tolerance.

Methods: Medical records of children diagnosed with food allergy who participated in oral food challenge at an allergy outpatient clinic (2009-2013) were reviewed for IgE antifood serology and concomitant oral food challenge outcomes, which were analyzed for associations by using logistic regression models and receiver operator characteristics curves.