There has been a dramatic increase in food allergy and other allergic conditions over the past decades.The prevalence of peanut allergy has increased from 0.5% a decade ago to between 1.0 and 1.8% now. Peanut allergy is the most common cause of life threatening food allergy. Parents with a peanut-allergic child often have a great deal of stress in attempting to ensure a peanut-free environment in the home, school, and play environments to prevent a life-threatening reaction. Parents often wonder if the brother or sister of the peanut allergic child will also have peanut allergy, sometimes asking the doctor to test the child before giving the child peanuts for the first time.
Usually, allergists do not perform testing to foods unless a child has already had an obvious allergic reaction to that food.
Our research question: Is the younger sibling (brother or sister) of a peanut allergic child more likely to have peanut allergy too?
Should allergy doctors test the younger siblings for peanut allergy even before they eat peanuts?
Findings: 560 SAGE children were contacted to fill out the Sibling Food Allergy survey. 92% completed the survey.
Peanut allergic children: 5.6% (29) of the SAGE children had peanut allergy, and eight children had positive skin tests but were able to eat peanuts.
There were 44 siblings in this group. Of those, 8.5% were allergic to peanuts.
Non-peanut allergic children: 94.4% (450) of children were not allergic to peanuts.
There were 853 siblings in this group. 1.3 % were allergic to peanuts.
Using the SAGE birth cohort study, it was shown that a sibling of a peanut-allergic child has a dramatic increased risk of developing peanut allergy (8.5% vs 1.3%). This risk is nearly 7 times greater than those who do not have a sibling with peanut allergy.
Conclusion: The study showed that siblings of peanut allergic children have a significantly increased risk of also developing a peanut allergy. The study recommends that siblings born into a family with a peanut-allergic child be assessed for peanut allergy by a qualified allergist before being fed this food for the first time. Depending how allergic they are, doctors may try to give these children peanuts in the clinic environment in order to watch for and treat reactions .
Should Younger Siblings of Peanut-Allergic Children Be Assessed by an Allergist before Being Fed Peanut? Liem JJ, Huq S, Kozyrskyj AL, Becker AB. Allergy Asthma Clin Immunol. 2008 Dec 15;4(4):144-9. Epub 2008 Dec