CLINICAL CHARACTERISTICS, ETIOLOGIES, AND OUTCOMES OF SEVERE EOSINOPHILIA IN PEDIATRIC PATIENTS

Abstract

<h3>Introduction</h3> There is limited data in pediatric patients with severe eosinophilia defined as absolute eosinophil count (AEC) >5000 cells/µL. The goal of this study is to examine patient characteristics and outcomes of severe eosinophilia in pediatrics. <h3>Methods</h3> A retrospective chart review was conducted for patients (≤18 years old) with severe eosinophilia at a tertiary pediatric hospital from August 2010 to August 2020. Demographics, AEC at presentation and peak, resolution time, medications, underlying diagnoses, and treatment during eosinophilia were evaluated. <h3>Results</h3> Of 139,000 CBCs reviewed, 45 patients had severe eosinophilia and 56% were male and 67% were Caucasian. Severe eosinophilia was most commonly found during infancy (33%). The median presentation AEC was 6.08 K/µL (range 5.02-28) and median peak AEC was 6.68 K/µL (5.02-42). The median resolution time was 43 days (interquartile range 11.5-141.5). Nearly all but 2 patients had secondary eosinophilia from other conditions including neoplasm (n=10), prematurity with infection (n=7), atopic dermatitis (n=5), parasitic infection (n=3), asthma (n=2), primary immunodeficiency (n=2), ulcerative colitis (n=1), systemic juvenile idiopathic arthritis (n=1). 28 patients were exposed to antibiotic or antiepileptic drug within 3 months of eosinophilia, but none thought to be primarily associated with eosinophilia. None had drug reaction with eosinophilia and systemic symptoms. Majority of patients had resolution of severe eosinophilia: 2 with hypereosinophilic syndrome received steroids, 29 treated for underlying condition, 4 with transient eosinophilia, and 10 with unknown outcome. <h3>Conclusion</h3> Severe eosinophilia was most common in infancy. Majority of patients had secondary eosinophilia with resolution after treatment of underlying disease.