This article is more than 5 years old. Information may no longer be current.

Siblings of allergic children often show food sensitivities not allergies

SAN ANTONIO — Siblings of children with food allergies were likely to have food sensitivity, but not likely to have the same food allergies, according to data presented at the 2015 American College of Allergy, Asthma and Immunology Annual Scientific Meeting.

“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,” Ruchi S. Gupta, MD, MPH, associate professor of pediatrics at the Northwestern Feinberg School of Medicine, said in a press release. “But testing for food allergies if a reaction hasn’t taken place can provide false-positives, as we saw in our research. More than half the kids in the study had a sensitivity to a food, but they weren’t truly allergic. Kids who have a food sensitivity shouldn’t be labeled as having a food allergy.”

Ruchi S. Gupta

The researchers assembled a cohort of 876 children aged younger than 21 years with at least one sibling with a documented food allergy. Food allergies were determined through clinical reaction history, specific immunoglobulin E and skin prick testing.

Study results showed that 53% of children who had siblings with a food allergy were sensitive to a food with a positive specific IgE or skin prick test, but had no symptoms of food allergy. Thirteen percent of children in this group had a confirmed food allergy.

“Our data strengthen the current recommendations discouraging testing of siblings of food-allergic children without a history of a symptomatic food ingestion,” Gupta told Infectious Diseases in Children. “We recommend that more research should be done using food challenge-based cohorts with siblings in order to help determine the absolute risk of food allergy development given a family history of food allergy in another child.”

Milk was the most common allergy among siblings of allergic children (5.9%), along with eggs (4.4%) and peanut (3.7%). Wheat caused the most common sensitization (36.5%), but not allergy, among siblings.

Matthew J. Greenhawt

“Food allergy tests perform poorly in terms of being able to predict future risk in someone who has never eaten the food before,” Matthew J. Greenhawt, MD, MBA, MSc, of the University of Michigan Health System and an Infectious Diseases in Children Editorial Board member, said in the release. “Our study showed that testing should be limited in order to help confirm a diagnosis, rather than as a sole predictor to make a diagnosis.” – by David Costill

Reference:
Gupta RS. Abstract 36. Presented at: American College of Allergy, Asthma and Immunology Annual Scientific Meeting; Nov. 5-9, 2015; San Antonio. 

Disclosure: The researchers report no relevant financial disclosures.