Implementing Primary Prevention for Peanut Allergy at a Population Level

Peanut allergy is increasingly common, with an estimated prevalence in children of 2% to 3% in the United States,¹ the United Kingdom,² and Australia.³ Decades of well-intentioned advice from specialist organizations to avoid introducing peanuts (and other nuts) into the diet of infants and young children may have contributed but is unlikely to have been the only reason for this increase. Evidence from a randomized clinical trial (RCT), the Learning Early About Peanut Allergy (LEAP) study, suggested that the introduction of peanut into the diets of infants at high risk of peanut allergy between 4 and 11 months decreases the risk of a clinical peanut allergy at the age of 5 years,⁴ with persistence of the protective effect at 6 years demonstrated by the follow-up study.⁵ The Enquiring About Tolerance (EAT) study examined early introduction of multiple foods, including peanut, from 4 months of age in a population not selected for atopic risk.² This study failed to show a protective effect for peanut introduction by intention-to-treat analysis, although a per-protocol analysis suggested a potential benefit.