Reactive eosinophilia is associated with inflammatory bowel disease and is more common in patients with ulcerative colitis (UC) compared with Crohn's disease. The prevalence rate of peripheral blood eosinophilia in patients with inflammatory bowel disease has been described to be as high as 30%-40% of patients in a pediatric study. The coexistence of hypereosinophilic syndrome (HES) and UC is uncommon. We present a 15-year-old boy with UC associated with HES who presented with chest pain and shortness of breath. Laboratory evaluation showed marked eosinophilia. Alternative causes of eosinophilia including eosinophilic leukemia, infections, or drug-induced eosinophilic pneumonia were ruled out. The patient was ultimately diagnosed with HES responsive to mepolizumab.
Keywords: eosinophilia; hypereosinophilic syndrome; ulcerative colitis.
Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.