IMPACT OF EARLY PEANUT INTRODUCTION GUIDELINES ON INFANT TREE NUT ALLERGY TESTING

Abstract

<h3>Introduction</h3> Tree nut allergy, like peanut allergy, is a common cause of severe food allergic reactions. The impact of the 2017 early peanut introduction guidelines on tree nut allergy testing in infants has not been well studied. <h3>Methods</h3> We performed a retrospective cohort study of infants less than age 1 year with Kaiser Permanente Northern California insurance coverage and had food-specific sIgE testing from January 2015 to December 2020. Our outcome of interest was sIgE testing rates for the following tree nuts: almond, Brazil nut, cashew, hazelnut, pecan, pistachio, and walnut. <h3>Results</h3> Among 3340 infants undergoing food-specific sIgE testing, the sIgE testing rates (per 1000 infants) increased for all tree nuts studied from 2015 to 2020 (p<0.001, Figure). Year-to-year analysis showed that sIgE testing rates increased for most tree nuts from 2017 to 2018 following publication of the early peanut introduction guidelines: almond (p=0.001), Brazil nut (p=0.001), hazelnut (p=0.001), pecan (p=0.004), and pistachio (p=0.002). sIgE testing rates for cashew and walnut also trended upward but decreased significantly from 2018 to 2019 following removal of a food allergy screening panel containing both nuts (p=0.01 for cashew, p=0.035 for walnut). <h3>Conclusion</h3> Infant sIgE testing rates increased significantly for all tree nuts following the 2017 early peanut introduction guidelines and decreased for selected tree nuts following removal of a food allergy screening panel. More studies are needed to assess the utility of tree nut sIgE testing in infants and the impact of early food introduction on tree nut allergy prevalence.