Parents of a food allergic child may understandably want younger siblings to undergo allergy screening before introducing them to potentially problematic foods.
However, the National Institute of Allergy and Infectious Diseases recommends not screening siblings prior to their initial exposure to a food. Their position is based on the high rate of false-positives in allergy testing, and a low risk of food allergy among siblings—which research supports.
A study published in the Journal of Allergy and Clinical Immunology indicates the risk of food allergy for the siblings of food allergic children is just “minimally higher” than for the general population. The research data showed:
- Just over half, 53 percent of the participating siblings of food allergic kids showed food sensitization when tested, but they experienced no allergy symptoms.
- About a third of the siblings (35 percent) screened negatively for allergy and had no reactions to food.
- Of the siblings, only 13.6 percent had a true food allergy.
“We...observed that testing might show sensitization to peanuts in a child who has never had peanuts, for example, but that might not mean that eating a peanut will provoke allergic symptoms in that child," said the study’s lead author Ruchi Gupta, MD.
"Our findings help support the National Institute of Allergy and Infectious Diseases practice guidelines to not screen siblings before the child's initial exposure to a food."
Gupta points out that screening kids who have never reacted to foods can lead to the avoidance of cuisine they may actually be able to tolerate and enjoy, plus avoiding a particular food increases the likelihood of developing an allergy to it.