Egg Allergies And Vaccinations
Children who have egg allergies have a hypersensitivity to eggs and egg-containing foods. Symptoms may include hives, dermatitis, angioedema (an allergic skin condition characterized by patches of swelling), wheezing, vomiting, diarrhea and, in some cases, anaphylaxis, a potentially life-threatening allergic reaction.
Most true food allergies last for only a brief period in a child's lifetime. In the time it takes for the child to develop a tolerance to the food, allergic reactions usually can be prevented by avoiding the offending food. Avoidance is not so easy, though, when it comes time to vaccinate a child who shows a sensitivity to eggs. because certain vaccinations — including the vaccination for yellow fever, mumps, rabies, influenza, and measles — are grown in an egg medium. Minute amounts of egg allergens can carry over into the vaccine and potentially cause an allergic reaction.
However, the current measles and mumps vaccines do not appear to contain enough egg proteins to cause problems. Recent studies have shown that children with egg allergy, including those with a history of a severe allergic reaction to eggs, are at low risk for anaphylactic reactions to measles or mumps vaccines, either given separately or as the combination measles-mumps-rubella (MMR) vaccine. In one study published in the New England Journal of Medicine, 54 children with documented egg allergy, including 26 with a history of anaphylaxis to eggs, received the MMR vaccine safely. Additionally, in this study children with egg allergies who had positive allergy skin tests to MMR did not have reactions to the full vaccine dose. Therefore, the current recommendation of the American Academy of Pediatrics is that children with egg allergy routinely can be given MMR, measles, or mumps vaccines without prior skin testing.
On the other hand, the yellow fever and influenza vaccines contain significant amounts of egg allergens and on rare occasions, can cause allergic reactions, including anaphylaxis. The influenza vaccine (flu shot) typically is not given to children with a history of severe egg allergy because of the risk of reaction to the shot and the availability of antiviral drugs that can prevent serious illness from the influenza virus.
Children with a history of anaphylaxis as a result of an egg allergy should undergo skin testing prior to receiving the yellow-fever vaccine. If the skin test is negative, the vaccine can be given. If the test is positive, the vaccine still can be given if necessary using a special desensitization protocol in which the vaccine is administered in multiple doses.