Introduction: Egg allergy is one of the most common food allergies in childhood. Administration of the measles, mumps, and rubella (MMR) vaccine is recommended in pediatric age. Despite the presence of traces of egg protein in its composition, the literature recommends MMR vaccine administration regardless of the patient’s past egg allergy history, identifying cases in which the administration should occur in hospital setting.
Purpose: To characterize the pediatric population referred to the Allergy and Clinical Immunology Department of Centro Hospitalar Universitário do Porto for MMR vaccine administration and investigate vaccination safety in children with egg allergy or sensitization.
Methods: This was a retrospective observational study of clinical records of children with confirmed or suspected egg allergy referred to the Allergy and Clinical Immunology Department for administration of the MMR vaccine between January 1, 2013 and December 31, 2019.
Results: Among 60 children studied, 90% presented symptoms upon egg intake, with cutaneous reactions being the most prevalent (67%) and four reported cases of anaphylaxis. Allergy to cow’s milk protein (55%), followed by allergy to other foods (45%) were the most frequent personal histories of allergic diseases. Asthma was identified in 10% of patients and was controlled in all cases. Among children referred for vaccination booster dose, one had had a reaction to the previous MMR vaccine dose. Three children developed late local skin reactions, and one had a late systemic reaction after vaccination. All children had negative oral food challenge.
Conclusion: MMR vaccine administration is safe and recommended in pediatric age, regardless of egg allergy history. However, immunization should be performed in hospital setting in children with a history of anaphylaxis due to egg allergy, previous anaphylactic reaction to MMR vaccine or one of its constituents, uncontrolled asthma with documented egg allergy, and uncontrolled asthma with allergy to a previous MMR vaccine dose.info:eu-repo/semantics/publishedVersio
