Understanding the feasibility and implications of implementing early peanut introduction for prevention of peanut allergy.
BACKGROUND A recent randomized trial (the Learning Early About Peanut Allergy [LEAP] study) provided evidence that earlier dietary peanut introduction reduces peanut allergy prevalence in high-risk infants. However, questions remain as to how to identify and target the "at-risk" population to facilitate timely introduction of peanut. OBJECTIVE We sought to use population-based infant peanut allergy data to understand feasibility and implications of implementing the LEAP trial intervention. METHODS Using the HealthNuts study cohort (n = 5276) of 1-year-old infants, we explored the impact of using various criteria to identify infants at high risk of developing peanut allergy, and the implications of skin prick test (SPT) screening before peanut introduction. RESULTS Screening all infants with early onset eczema and/or egg allergy could require testing 16% of the population and would still miss 23% of peanut allergy cases; 29% of screened infants would require clinical follow-up because of being SPT-positive. Around 11% of high-risk infants were excluded from the LEAP study because of an SPT wheal size of more than 4 mm to peanut at baseline; data from the HealthNuts study suggest that 80% of these would be peanut allergic on food challenge. There were no life-threatening events among either low- or high-risk infants whose parents chose to introduce peanut at home in the first year of life, or in 150 peanut-allergic infants during hospital-based challenges. CONCLUSIONS Based on this large epidemiological study, a population program aiming to identify and screen all infants at risk of peanut allergy would pose major cost and logistic challenges that need to be carefully considered. Further research might be required to provide data for low-risk infants.