By Martina M. McGrath, MD
July 6, 2016
Food allergies are an increasing public health issue. Recent years have seen a dramatic rise in prevalence of peanut allergy, from 0.4% in 1997 to 1.4% in 2008. Today, peanut allergy is the most common cause of anaphylaxis and food allergy related deaths in the United States. Several recent landmark studies have furthered our understanding of the development of peanut allergy and indicated an alternative approach to the prior dogma of delayed introduction and strict avoidance of potential food allergens.
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The LEAP study, published in NEJM in Feb 2015, randomized 640 infants, under 11 months of age, at high risk of peanut allergy to either peanut consumption or avoidance until age five years. All participants underwent skin testing and open label peanut challenge at baseline. Those able to tolerate peanuts were then assigned to peanut consumption and advised to take 2g of peanut three times weekly.
The results are striking. In those infants without sensitization at baseline (i.e., negative skin testing), 1.9% of the peanut-exposed group versus 13.7% of the peanut-avoidance group were allergic, an 86.1% relative reduction in prevalence of peanut allergy. In those who were already sensitized and with positive skin testing at baseline, 35.3% of the avoidance group and 10.6% of the consumption group were peanut allergic at age 60 months. This 24.7% difference represents a 70% relative decrease in allergy prevalence.
These compelling findings led to a consensus communication, issued from an international group of 10 allergy and pediatric medical societies, urging early introduction of peanut as a protective strategy for high-risk infants. This dramatic shift in recommendations underpins the significance of this study and highlights the importance utilizing data from well-designed, randomized studies when making such recommendations.
Randomized Trial of Peanut Consumption in Infants at Risk for Peanut Allergy. Du Toit, G et al. N Engl J Med 2015; 372:803-813
Consensus communication on early peanut introduction and the prevention of peanut allergy in high-risk infants. Fleischer DM, Sicherer S, Greenhawt M, et al.. J Allergy Clin Immunol 2015;136:258-261
Dr. Martina McGrath is an Instructor in Medicine at Harvard Medical School, and a member of the Renal Division, Department of Medicine, at Brigham and Women’s Hospital, both in Boston.