Oral food challenges

Oral food challenge (OFC) is a procedure that is conducted most commonly by allergist/immunologists in their office or in food allergy centers to confirm a food allergy or to confirm tolerance to the food. The procedure as conducted in clinical practice is mostly open food challenge and, in research, a double-blind, placebo controlled food challenge. OFC has associated risks that can be minimized by having the challenges conducted by trained personnel who are prepared to treat allergic reactions and who have rescue medications available. However, OFCs have tremendous benefits to the patients and their families, including the potential to determine that a food is no longer an allergen and can be introduced into the diet. Even OFCs that result in clinical reactions have the benefit of confirming the food allergy and demonstrating the therapeutic effect of the rescue medications. The study of the outcomes of OFC has shed light on food allergy reactions and characteristics of the patients with food allergy as well as on the value of other diagnostic tests compared with OFC. OFCs have helped establish food allergy thresholds, confirm that subjects enrolled in research studies have the allergy, and demonstrate the response to the therapies tested in terms of ameliorating the allergic response or raising the reaction threshold. OFCs have also been used to promote the recent guidelines for the prevention of peanut allergy by identifying the infants at risk for peanut allergy but who are not allergic yet.

Confirmed Hypoallergenicity of a Novel Whey-Based Extensively Hydrolyzed Infant Formula Containing Two Human Milk Oligosaccharides

Background: We sought to determine whether an extensively hydrolyzed formula (EHF) supplemented with two human milk oligosaccharides (HMO) was tolerated by infants with cow’s milk protein allergy (CMPA). Methods: A whey-based EHF (Test formula) containing 2′fucosyl-lactose (2′FL) and lacto-N-neotetraose (LNnT) was assessed for clinical hypoallergenicity and safety. The Control formula was a currently marketed EHF without HMO. Children with CMPA, aged 2 months to 4 years, were assessed by double-blind, placebo-controlled food challenges (DBPCFC) to both formulas, in randomized order. If both DBPCFC were negative, subjects participated in a one-week, open food challenge (OFC) with the Test formula. Symptoms and adverse events were recorded. Hypoallergenicity was accepted if at least 90% (with 95% confidence intervals) of subjects tolerated the Test formula. Results: Of the 82 children with CMPA that were screened, 67 (intention-to-treat [ITT] cohort—mean age 24.5 ± 13.6 months; range 2–57; 45 [67.2%] male) were randomized to receive either the Test or the Control formula during the first DBPCFC. Of these, 64 children completed at least one DBPCFC (modified intention-to-treat [mITT] cohort). Three children were excluded due to protocol deviations (per protocol [PP] cohort; n = 61). There was one allergic reaction to the Test, and one to the Control formula. On the mITT analysis, 63 out of 64 (98.4%; 95% CI lower bound 92.8%), and on the PP analysis 60 out of 61 (98.4%; 95% CI lower bound 92.5%) participants tolerated the Test formula, confirming hypoallergenicity. Conclusion: The whey-based EHF supplemented with 2′FL and LNnT met the clinical hypoallergenicity criteria and can be recommended for the management of CMPA in infants and young children.