PEANUT COMPONENT TESTING: NOT THE ONLY COMPONENT

Abstract

<h3>Introduction</h3> Peanut allergy is a common condition affecting approximately 2-3% of the American pediatric population. Peanut component testing has become an increasingly widespread tool used by physicians to assess the likelihood of having a systemic reaction after peanut ingestion. Traditionally, evidence of sensitization to Ara h1-3 is the most important indicator of peanut-induced anaphylaxis, with sensitization to Ara h2 being the most clinically relevant. <h3>Case Description</h3> A 20-month-old female patient presented to clinic for an oral food challenge with peanut. She had recently been evaluated in allergy clinic after a possible systemic reaction to peanut exposure approximately 1 year earlier. Previous laboratory testing revealed a peanut sIgE of 0.52kU/L. In addition, component testing was performed with the Ara h6 sIgE of 0.52kU/L, but negative for the presence of sIgE to other peanut components. During the challenge, she developed diffuse urticaria. An injection of 0.15 mg intramuscular epinephrine was administered into the anterolateral thigh with improvement in symptoms. Approximately 30 minutes later, new urticaria developed and she was administered a second dose of 0.15 mg intramuscular epinephrine into the anterolateral thigh with resolution of symptoms. <h3>Discussion</h3> This case highlights a limitation of peanut component testing. While the presence of sIgE to Ara h2 may increase the risk of anaphylaxis with peanut ingestion, it is not present in all patients that will experience a reaction. Informed consent processes should not be affected by reassuring results of component testing when considering an oral food challenge.