Families with one child who has a food allergy shouldn't necessarily assume their sibling will have the same allergy.
According to a new study published in the Journal of Allergy and Clinical Immunology, it turns out only about one in 10 sibling of kids with a specific food allergy actually end up being allergic to the same thing.
The researchers studied 1,120 biological siblings of children with a diagnosed food allergy using patient histories and blood testing, and found that while 53 percent of the siblings had a food sensitivity, they did not experience any food allergy symptoms. In fact, only about 13 percent had a true food allergy.
So what gives? According to allergist and lead author Dr. Ruchi Gupta, testing for food allergies if a reaction hasn't taken place can provide false-positives. "More than half the kids in the study had a sensitivity to a food, but they weren't truly allergic," he explained, adding that kids who have a food sensitivity shouldn't be labeled as having a food allergy.
Why? Because by avoiding a food you think you are allergic to, you are actually increasing the risk of developing an allergy to it. Which is why Dr. Gupta says the findings underscore the notion that allergy testing in siblings should be used judiciously—and not before the child's initial exposure to a food—in order to minimize the impact of possible misdiagnosis.
"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," he explained. "Screening siblings for allergies should be limited."