An Evolving Approach to the Diagnosis of Eosinophilic Esophagitis

Abstract

Eosinophilic esophagitis (EoE) is a chronic allergic/ immune-mediated esophageal disease. Knowledge related to the clinical presentation, pathogenesis, epidemiology, natural history, treatment, and outcomes of EoE has rapidly evolved over the past 2 decades. This article focuses on the similarly evolving diagnostic framework for EoE. In the initial clinical guidelines, diagnosis of EoE was based on symptoms of esophageal dysfunction; at least 15 eosinophils per high-power field (eos/hpf) on esophageal biopsy; and either a lack of response to high-dose proton pump inhibitor (PPI) therapy, or normal pH monitoring. The first 2 criteria have remained largely unchanged; however, the role of PPIs has been controversial, particularly due to the recognition of PPI-responsive esophageal eosinophilia (PPI-REE), in which patients with suspected EoE experience resolution of symptoms and esophageal eosinophilia with PPI therapy. A quickly expanding evidence base has found that most adult patients with EoE and PPI-REE share similar clinical, endoscopic, histologic, immunologic, and molecular characteristics prior to the use of PPIs. Because of this, the most recent diagnostic guidelines have removed the lack of response to PPIs as a diagnostic criterion; PPIs are now better considered as a treatment for esophageal eosinophilia. EoE should currently be suspected on a clinical basis when there are symptoms of esophageal dysfunction and at least 15 eos/hpf on esophageal biopsies. A history of atopy and endoscopic signs of EoE are strongly supportive of the diagnosis. However, the diagnosis cannot be confirmed until a thorough evaluation of other potential causes of esophageal eosinophilia has been performed.

Keywords: Eosinophilic esophagitis; diagnosis; eosinophil; esophageal eosinophilia; esophagus.

Figure.

The first case report of eosinophilic esophagitits (EoE) was published in 1977; however, the condition was recognized as a distinct entity in 3 seminal publications between 1993 and 1995. The first consensus guidelines were published in 2007, establishing a diagnostic framework for EoE. These guidelines were updated in 2011, when PPI-REE was introduced as a concept. Management guidelines for the United States were published in 2013, followed by pediatric guidelines in 2014. The updated European guidelines, published in 2017, and international consensus guidelines, to be published in 2018, removed PPI nonresponse as a diagnostic criterion. AGREE, A Working Group on PPI-REE; PPI, proton pump inhibitor; PPI-REE, PPI-responsive esophageal eosinophilia.