AUTHOR=Chong Albert C. , Izadi Neema , Chwa Won Jong , Tam Jonathan S. 

TITLE=Fruitful or unfruitful: strawberry and tomato specific immunoglobulin E testing at a tertiary pediatric center

JOURNAL=Frontiers in Allergy

VOLUME=4

YEAR=2023

URL=https://www.frontiersin.org/journals/allergy/articles/10.3389/falgy.2023.1277631

DOI=10.3389/falgy.2023.1277631

ISSN=2673-6101

ABSTRACT=<sec><title>Background</title><p>Suspected strawberry and tomato (S/T) food allergy (FA) can be evaluated using specific immunoglobulin E (sIgE) testing despite its low specificity and positive predictive value.</p></sec><sec><title>Objective</title><p>This study aims to understand ordering patterns for S/T sIgE testing and identify relevant factors to clinical decision-making.</p></sec><sec><title>Methods</title><p>We retrospectively reviewed 814 patients with sIgE testing available for strawberries (651), tomatoes (276), or both (113) from January 2012 to May 2022 at a tertiary pediatric hospital. Patient demographics, provider specialty, and reasons for testing were collected. Student’s <italic>t</italic>-test and multiple regression analyses were performed to test the association between the S/T sIgE level and clinically relevant outcome (CRO) status. Fisher’s exact test and general linear models were used to evaluate and compare potential predictive factors for CRO status.</p></sec><sec><title>Results</title><p>Allergy and immunology, gastroenterology, and general pediatrics ordered most S/T sIgE testing. Testing was ordered most frequently for non-IgE-mediated gastrointestinal symptoms, mild possible IgE-mediated reactions, and eczema. Testing was most often ordered for infants and school-age children. Mean sIgE levels were higher for S/T tests resulting in a CRO when controlling for other predictor variables (<italic>p</italic> = 0.015; <italic>p</italic> = 0.002 for S/T, respectively). Only 2.2% and 5.4% of tests resulted in a CRO for S/T, and severe allergy was rare. Testing for non-IgE-mediated GI symptoms or eczema, or in non-atopic patients, yielded no CROs. Exposure and reaction history of present illness (ERH) was associated with CROs (<italic>p</italic> &lt; 0.001; <italic>p</italic> = 0.04) with a high negative predictive value (99.5%; 100%) and low positive predictive value (11.5%; 15.0%). ERH (<italic>p</italic> &lt; 0.001, <italic>η</italic><sup>2</sup> = 0.073; <italic>p</italic> = 0.009, <italic>η</italic><sup>2</sup> = 0.123) was a more significant predictor than the sIgE level (<italic>p</italic> = 0.002, <italic>η</italic><sup>2</sup> = 0.037; <italic>p</italic> = 0.212, <italic>η</italic><sup>2</sup> = 0.030) for CRO status.</p></sec><sec><title>Conclusion</title><p>The diagnosis of S/T food allergy is made primarily based on clinical history. S/T sIgE testing for children and adolescents should be avoided for patients without an ERH and in the workup of non-IgE-mediated GI symptoms. Testing for eczema and non-atopic patients is likely low-yield.</p></sec>