Study finding turns peanut-allergy avoidance strategy on its head

Eating peanuts in the first year of life dramatically reduces the likelihood that an infant at moderate risk for peanut allergy will develop the allergy, a randomized controlled trial in the United Kingdom showed. This finding directly contradicts the conventional wisdom that to prevent peanut allergy, parents should exclude this food from their infants’ diets.

Investigators divided 640 atopic infants (with severe eczema, egg allergy, or both) aged from 4 months to 11 months into 2 groups-those who had a positive skin-prick test for peanut allergy in 1 group and those who did not in another. Participants in each of these 2 groups were then assigned to a group that would consume peanuts or to 1 that would not. Infants in the peanut-eating group received at least 6 grams of peanut protein (about 24 peanuts) a week, either in a peanut butter/puffed maize snack food or peanut butter itself, until they were aged 60 months. Infants in the avoidance group had no peanut protein until they were aged 60 months. Investigators performed clinical assessments periodically during the 5-year study period.

At the conclusion of the study, of the 530 infants who initially had negative results on the skin-prick test, 13.7% in the avoidance group had peanut allergy compared with 1.9% in the consumption group. Among the 98 infants with positive skin-prick results, only 10.6% of those fed food containing peanuts had developed peanut allergy compared with 35.3% of those whose parents had avoided feeding them peanuts (Du Toit G, et al. N Engl J Med. 2015;372[9]:803-813).

Commentary: This randomized, controlled study was a follow-up to the researchers’ 2008 observation that peanut allergy is 10 times more common in Jewish children raised in England versus those raised in Israel where peanut is commonly introduced early as an ingredient in teething biscuits. Children at highest and lowest risk of peanut allergy were excluded from the study (those who reacted to a test dose and those who did not have severe eczema or egg allergy at baseline). The mechanism of action seems to be similar to the tolerance provided by immunotherapy to other antigens: reduction in immunoglobulin E to peanut and an increase in immunoglobulin G4 to the antigen.

The findings in this study are dramatic. They may well change how we approach the increase in peanut allergy in the 21st century. If you have an infant patient with a strong family history of peanut allergy, it is worth discussing this article with an allergist in your community. -Michael G Burke, MD

Ms Freedman is a freelance medical editor and writer in New Jersey. Dr Burke, section editor for Journal Club, is chairman of the Department of Pediatrics at Saint Agnes Hospital, Baltimore, Maryland. The editors have nothing to disclose in regard to affiliations with or financial interests in any organizations that may have an interest in any part of this article.