Differences in Egg and Milk Food Challenge Outcomes Based on Tolerance to the Baked Form

Abstract

To determine if a history of tolerance versus avoidance of baked egg or cow’s milk influenced the outcomes of an oral food challenge to egg or whole cow’s milk.The study included 569 pediatric patients who underwent egg or cow’s milk oral challenges at the Children’s Hospital of Philadelphia from 2012 to 2015.This was a retrospective chart review of pediatric patients who underwent whole egg and cow’s milk oral food challenges.More patients passed the whole egg food challenge if they previously tolerated baked egg (75%) versus avoidance (58%, P = .01) or never ingested (45%, P < .0001). Among the positive reactions, those patients who tolerated baked egg reacted at higher doses (3.0 g) and required epinephrine less often (10%) than those patients with egg avoidance (0.69 g, P = .03; 22%, P = .02) or who never ingested (0.88 g, P = .01; 32%, P = .0001). No difference was found among patients with cow’s milk allergy. Those who never ingested egg or cow’s milk had the poorest oral food challenge outcomes and the highest rates of atopic dermatitis (66% for patients with egg allergy and 86% for patients with milk allergy).This study shows that children who were known to be able to tolerate baked egg had higher food challenge pass rates (tolerance). Additionally, in those patients who did react, they were able to tolerate higher doses and had less-severe reactions if they previously tolerated baked egg. This association was not observed with patients with cow’s milk allergy.Known tolerance of baked egg may be a helpful marker for identifying children who will have more favorable food challenge outcomes. Although the effects of including baked egg in the diet on altering the natural history of egg allergy remains inconclusive, the results of this study support that tolerance of baked egg may help to promote tolerance of concentrated egg. Patients should be evaluated by an allergist early to possibly allow for introduction of baked egg into the diet. If baked egg tolerance has been established, the pediatrician can encourage parents to continue it in the diet. Further studies are needed to determine if the same benefit may be seen with cow’s milk and identify markers for favorable food challenge outcome.