Allergic Adverse Reactions Following Measles-Mumps-Rubella Vaccination in Children with Food Allergy: A Prospective Multicenter Study

<b><i>Introduction:</i></b> The aim of this study was to determine the frequency and risk factors of allergic adverse reaction following measles-mumps-rubella (MMR) vaccination in children with egg and/or cow's milk allergies. <b><i>Methods:</i></b> Children with cow's milk and/or egg allergy were included. Patients with IgE-mediated cow's milk allergy were subjected to skin tests with MMR vaccines before vaccination. For patients with a positive skin test, administration of an alternative vaccine not containing the suspected excipient was planned. In case an alternative vaccine is not available, the MMR vaccine is planned to be administered with a gradual desensitization protocol. <b><i>Results:</i></b> Two hundred two patients (133 male and 69 female) with a mean age of 14.9 ± 11.9 months were evaluated. Of the patients, 126 (62.4%) received Tresivac®, while 76 (37.6%) received Priorix®. Before vaccination, 84 patients underwent skin testing with the vaccine, and the test was positive in 7 patients. Allergic reactions were observed in 12 patients (urticaria in 10 patients, angioedema in 1 patient, and anaphylaxis in 1 patient). Egg white-specific IgE (spIgE) levels were found to be higher in patients with egg-allergy who developed allergic reactions to MMR vaccines. The receiver operating characteristic (ROC) analysis identified a cut-off value of 6.5 kU/L for egg white-spIgE. In patients who developed allergic reactions following alpha-lactalbumin-containing vaccine, egg white-spIgE and cow's milk-spIgE levels were significantly higher compared with those without reactions. In the ROC analysis for predicting allergic reactions following Tresivac® vaccination, the cut-off values were as follows: egg white-spIgE: 6 kU/L, cow's milk-spIgE: 12.5 kU/L. <b><i>Conclusion:</i></b> It was determined that the cut-off values for cow's milk and egg white spIgE were found to be significant in identifying children at risk for allergic reactions following MMR vaccination. Children with food allergies who had a family history of atopy were found to have a higher risk of allergic reactions.