Study: Siblings Don't Always Have The Same Food Allergies

Research has found that when a child has some food allergy, his or her siblings aren't necessarily allergic to the same food as well.

"Too often, it's assumed that if one child in a family has a food allergy, the other kids need to be tested for food allergies," said the study's lead author and allergist Dr. Ruchi Gupta, an associate professor of pediatrics at Northwestern University in Evanston, Ill., in a press release.

Allergies are something that cause parents to be wary of what they feed to their kids. When one child in the family responds to an allergen, there's a tendency for parents to avoid feeding the same food to everyone in the family.

“The risk of food allergy in one sibling, based on the presence of food allergy in another, has never been completely clear,” said allergist and study co-author Matthew Greenhawt, MD, MBA, MSc.

The study, presented at the annual meeting of the American College of Allergy, Asthma, and Immunology (ACAAI), involved 1,120 children who had a sibling with a documented food allergy.

Of the participating children, it was found that although more than half (53 percent) had a sensitivity to some food allergens, only less than a quarter (13 percent) had an actual food allergy. The allergies of the kids were confirmed by checking their clinical history of previous allergic reactions to food, as well as blood testing and skin prick testing.

An allergic response to food would yield symptoms such as vomiting or stomach cramps, hives, wheezing, shortness of breath, tightness in the throat, dizziness, or feelings of faintness.

James Li, M.D., PhD., of the Mayo Clinic, said that most people often confuse food allergies to food intolerance.

“A true food allergy causes an immune system reaction that affects numerous organs in the body,” wrote Li. “It can cause a range of symptoms. In some cases, an allergic reaction to a food can be severe or life-threatening. In contrast, food intolerance symptoms are generally less serious and often limited to digestive problems.”

“If you have a reaction after eating a particular food, see your doctor to determine whether you have a food intolerance or a food allergy,” advised Li.

Gupta added that unless kids who've had allergic reactions are tested positive for allergies, they shouldn't be labeled as such.

“More than half the kids in the study had a sensitivity to a food, but they weren’t truly allergic,” Gupta explained. “Kids who have a food sensitivity shouldn’t be labeled as having a food allergy.”