Ovomucoid Is Not Superior to Egg White Testing in Predicting Tolerance to Baked Egg

BACKGROUND: Children with egg allergy may tolerate baked egg products. Ovomucoid specific IgE (sIgE) antibody levels have been suggested to predict outcomes of baked egg challenges. OBJECTIVE: We determined the relationship of ovomucoid and egg white sIgE levels and egg white skin prick test (SPT) wheal size with baked egg challenge outcome. METHODS: Retrospective review of 1186 patients who underwent ovomucoid sIgE blood testing. Subset analysis was of 169 patients who underwent baked egg food challenges. RESULTS: Egg white sIgE, ovomucoid sIgE, and egg white SPT were different among those eating regular egg, eating baked egg only, or avoiding all egg (P < .001 for all). One hundred forty-two of 169 patients (84.0%) passed baked egg challenges. We were able to establish >90% predictive values for passing baked egg challenge for egg white sIgE, ovomucoid sIgE, and egg white SPT. No patient with egg white SPT wheal <3 mm failed a baked egg challenge. Receiver operating characteristic curve analysis of egg white sIgE, ovomucoid sIgE, and egg white SPT showed areas under the curve of 0.721, 0.645, and 0.624, respectively. No significant difference was observed among these immunologic parameters in their abilities to predict baked egg challenge outcome (P = .301). CONCLUSION: Most children with egg allergy in this study passed baked egg challenges. Ovomucoid sIgE, although a useful clinical predictor of baked egg tolerance, was not superior to egg white SPT or sIgE in predicting outcome of baked egg challenge. (C) 2013 American Academy of Allergy, Asthma & Immunology