Q: My daughter has developed an egg allergy at 12 months. At the appointment where tests confirmed this, the allergist mentored being “mindful of possible peanut allergy”. I’m confused: are these two allergies related? And if so, what can I do to be careful?
Dr. Sharma: Allergies to egg and peanut often go together. For example, in a 2007 study of children with peanut allergy, two-thirds of them had an allergy or positive allergy test to another food, with egg being the most common, affecting over half.
Children with egg allergy are therefore considered to have a higher risk of developing peanut allergy. A recent landmark study investigated whether early feeding of peanut to these “high-risk” infants, who had either egg allergy, eczema or both, could prevent later peanut allergy.
Dr. Gideon Lack and colleagues at King’s College London found in the LEAP (Learning Early About Peanut Allergy) study that regular consumption of peanut starting between four to 11 months reduced the odds of peanut allergy at age 5 years by 70-80 percent. The infants first had a skin test to peanut performed, and were enrolled in the study only if their results were negative or very small.
Based on the LEAP study results, professional groups and expert panels are now formulating guidelines for the management of “high-risk” infants such as your daughter. For her case, you should seek your allergist’s advice about the next steps. He or she may recommend allergy testing to peanut, and either introduction of peanut at home if the result is negative, or a supervised food challenge if the result is mildly positive.
The authors of the LEAP study suggest there is a narrow window of opportunity to prevent peanut allergy, so early evaluation appears to be important in “high-risk” children like your daughter.
See Dr. Wade Watson’s take on the question here.
Dr. Sharma is an allergist, clinical researcher and assistant professor of pediatrics. He is Clinical Chief of the Division of Allergy and Immunology at Children’s National Health System in Washington, D.C. and Director of the Food Allergy Program. Questions submitted below will be considered for answer in the magazine.