It's not uncommon for siblings to have food insensitivities or common allergies, but new research shows that food allergies are not often shared. It's relatively rare for siblings to share an allergy to the same substances.
The study, presented at the American College of Allergy, Asthma, and Immunology's annual meeting, conlcuded that while just over half of all children have a food sensitivity to something their siblings are allergic to, few have an actual allergy in common. Misdiagnosis, they say, can have negative consequences.
The perceived risk of a common allergy after diagnosis for one child is often the impetus for screening another, said Dr. Matthew Greenhawt in a press release. Greenhawt is an allergist at the University of Michigan and a co-author on the study.
53 percent with a food sensitivity, but only 13 percent with a common allergy.
The study worked with 1,120 children with a sibling diagnosed with a food allergy. Allergies were confirmed using clinical histories of the children and specific blood tests and food reactions. The confusion between a sensitivity and actual allergy is often the reason a parent will assume both children have a common allergy.
The difference between the two is dramatic, however, with a sensitivity merely causing discomfort or light reactions when relatively large amounts of the food are consumed. In an allergy, even small amounts can result in serious effects such as vomiting, diarrhea, or life-threatening anaphylaxis. At the same time, misdiagnosing a child with food sensitivity as being allergic can mean that they suffer anxiety and worry for no appropriate reason.