Allergy Update: Most siblings of food-allergic children won’t develop the same food allergy

little boy reaching hand into a container of in-shell peanutsMany parents of food-allergic children have concerns about the development of food allergies in their other children. We’ve talked about the benefits of early exposure in infants, but for some children that are labelled high-risk, they may not have the opportunity for this early introduction. [Editor’s note: Infants considered at high-risk for developing allergies are usually defined as having a first-degree relative (at least one parent or sibling) with an allergy.]

New research out of the Ann & Robert H. Lurie Children’s Hospital of Chicago, as reported in the Journal of Allergy and Clinical Immunology, has found that just because an older sibling has a food allergy doesn’t mean that the younger sibling(s) will be affected. Many parents with a food-allergic child will bring their subsequent children for allergy screenings before exposing them to the sibling’s allergen, but the study cautions against this practice.

In a study of 2,834 children, 53% of participants had a positive food serum-specific IgE or skin prick test, but no reported symptoms of food allergy. This style of screening may lead to “negative consequences related to potential misdiagnosis and unnecessary avoidance of a food” with a high rate of false positives. For example, a child that has never been exposed to peanuts – a common scenario should their sibling be allergic – may show slight sensitivity in a test, but no allergic reaction.

Meanwhile, only 13.6% of siblings of children with a food allergy were both sensitized and clinically reactive to the same food. Milk was the most common food allergy shared by siblings (5.9%), with peanuts ranked third (3.7%) after eggs (4.4%). These findings are only slightly higher than the general population.


To access the full report, click the following link: Food Allergy Sensitization and Presentation in Siblings of Food Allergic Children