Division of Allergy and Immunology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, United States.
Front Immunol. 2018 Sep 3;9:1944. doi: 10.3389/fimmu.2018.01944. eCollection 2018.
Hypereosinophilia (HE) is currently defined by a peripheral blood absolute eosinophil count (AEC) of ≥1,500 cells/microL. Although mild blood eosinophilia (AEC 500-1,500 cells/microL) is observed relatively frequently within the pediatric population, persistent HE is uncommon and should prompt additional clinical evaluation. While the clinical manifestations and underlying etiologies of HE in adults have been well-characterized, there is a paucity of data on HE in children. Limited evidence suggests that many similarities between adult and pediatric HE likely exist, but some important differences remain between these populations. The evaluation of HE in children can be challenging given the broad differential diagnosis, which includes primary hematologic disorders and secondary eosinophilia in which the increased eosinophil levels are propagated by disease states that promote eosinophil production and survival. On the basis of the underlying etiology, clinical manifestations can range from benign, self-resolving elevations in the AEC to life-threatening disorders with the potential for significant end-organ damage. Given the broad differential diagnosis of HE, it remains essential to systematically approach the evaluation of unexplained HE in children. This review will discuss the differential diagnosis for pediatric HE, highlighting etiologies that are more prevalent within the pediatric population. Additionally, a summary of the epidemiology of pediatric HE will be presented, with focus on some of the differences that exist between pediatric and adult HE. Finally, a directed approach to the diagnostic evaluation of children with HE will be discussed.
嗜酸性粒细胞增多症（HE）目前的定义为外周血绝对嗜酸性粒细胞计数（AEC）≥1500 个/微升。虽然儿科人群中相对频繁地观察到轻度血液嗜酸性粒细胞增多症（AEC 500-1500 个/微升），但持续性 HE 并不常见，应引起额外的临床评估。虽然成人 HE 的临床表现和潜在病因已得到很好的描述，但儿童 HE 的资料有限。有限的证据表明，成人和儿童 HE 之间可能存在许多相似之处，但这两个群体之间仍存在一些重要差异。由于广泛的鉴别诊断，儿童 HE 的评估具有挑战性，其中包括原发性血液疾病和继发性嗜酸性粒细胞增多症，后者的嗜酸性粒细胞水平升高是由促进嗜酸性粒细胞生成和存活的疾病状态传播的。基于潜在病因，临床表现范围从良性、自限性的 AEC 升高到危及生命的疾病，可能导致重要的终末器官损伤。鉴于 HE 的广泛鉴别诊断，仍然需要系统地评估儿童不明原因的 HE。这篇综述将讨论儿童 HE 的鉴别诊断，强调儿科人群中更常见的病因。此外，还将介绍儿童 HE 的流行病学摘要，重点介绍儿科和成人 HE 之间存在的一些差异。最后，将讨论针对 HE 儿童的诊断评估的针对性方法。
