Study: Most siblings of food-allergic kids don't also develop the food allergy

Neither of my kiddos have food allergies (not yet, anyway—knock on wood) but I know how difficult it is for my friends who have to be hyper-vigilant about what their kids put in their mouths. And just because a parent knows how to manage an allergy—how to cook with alternative ingredients, how to read food labels, how to administer an EpiPen—doesn’t mean they want that potentially life-long challenge for their kids.

With that in mind, there’s good news today for parents with an older, food-allergic child: A study out of the Ann & Robert H. Lurie Children's Hospital of Chicago, published in the Journal of Allergy and Clinical Immunology, has found that just because an older sibling in a family has a food allergy doesn’t mean younger siblings will also be affected.

Parents with one allergic child often wonder if subsequent children should be tested before introducing the allergic food of the older sibling, but this study says no. The research indicates that the risk of the sibling having the same food allergy is only marginally higher than the general population. There’s also a high level of false positives and food sensitization in kids who have never been exposed to the allergen (meaning a kid who has never had peanuts might show a slight sensitivity after repeated testing, but not an allergic reaction), which can lead to a child avoiding a food to which they aren’t really allergic. Only 13.6% of siblings were both sensitized and clinically reactive to the same food. Milk allergy was the most common allergy among siblings (5.9%), followed by egg allergy (4.4%) and peanut allergy (3.7%).

"Routine screening without a history of allergic food reactions might lead to unnecessary food avoidance in kids who can actually tolerate that food, which impacts quality of life and nutrition," says lead author, pediatrician and researcher Ruchi Gupta, who herself has a daughter with food allergies. "Food avoidance also increases the risk of developing an allergy to that food."

Read more: New hope for kids with serious food allergies Could your kid have celiac disease? How to know if your kid has a food allergy or food intolerance