Introduction
Eosinophilic esophagitis (EoE) has transformed over the past 3 decades from a rarely encountered entity to one of the most common causes of dysphagia in adults.1 Given the marked rise in prevalence, the early-career gastroenterologist will undoubtedly be involved with managing this disease.2 The typical presentation includes a young, atopic male presenting with dysphagia in the outpatient setting or, more acutely, with a food impaction when on call. As every fellow is keenly aware, the calls often come late at night as patients commonly have meat impactions while consuming dinner. Current management focuses on symptomatic, histologic, and endoscopic improvement with medication, dietary, and mechanical (i.e., dilation) modalities.
EoE is defined by the presence of esophageal dysfunction and esophageal eosinophilic inflammation with ≥15 eosinophils/high-powered field (eos/hpf) required for the diagnosis. With better understanding of the pathogenesis of EoE involving the complex interaction of environmental, host, and genetic factors, advancements have been made as it relates to the diagnostic criteria, endoscopic evaluation, and therapeutic options. In this article, we review the current management of adult patients with EoE and offer practical guidance to key questions for the young gastroenterologist as well as insights into future areas of interest.
What should I consider when diagnosing EoE?
Symptoms are central to the diagnosis and clinical presentation of EoE. In assessing symptoms, clinicians should be aware of adaptive “IMPACT” strategies patients often subconsciously develop in response to their chronic and progressive condition: Imbibing fluids with meals, modifying foods by cutting or pureeing, prolonging meal times, avoiding harder texture foods, chewing excessively, and turning away tablets/pills.3 Failure to query such adaptive behaviors may lead to an underestimation of disease activity and severity.
An important aspect to confirming the diagnosis of EoE is to exclude other causes of esophageal eosinophilia. Gastroesophageal reflux disease (GERD) is known to cause esophageal eosinophilia and historically has been viewed as a distinct disease process. In fact, initial guidelines included lack of response to a proton pump inhibitor (PPI) trial or normal esophageal pH monitoring as diagnostic criteria.4 However, as experience was garnered, it became clear that PPI therapy was effective at improving inflammation in 30%-50% of patients with clinical presentations and histologic features consistent with EoE. As such, the concept of PPI–responsive esophageal eosinophilia (PPI-REE) was introduced in 2011.5 Further investigation then highlighted that PPI-REE and EoE had nearly identical clinical, endoscopic, and histologic features as well as eosinophil biomarker and gene expression profiles. Hence, recent international guidelines no longer necessitate a PPI trial to establish a diagnosis of EoE.6
The young gastroenterologist should also be mindful of other issues related to the initial diagnosis of EoE. EoE may present concomitantly with other disease entities including GERD, “extra-esophageal” eosinophilic gastrointestinal diseases, concomitant IgE-mediated food allergy, hypereosinophilic syndromes, connective tissue disorders, autoimmune diseases, celiac disease, and inflammatory bowel disease.3 It has been speculated that some of these disorders share common aspects of genetic and environmental predisposing factors as well as shared pathogenesis. Careful history taking should include a full review of atopic conditions and GI-related symptoms and endoscopy should carefully inspect not only the esophagus, but also gastric and duodenal mucosa. The endoscopic features almost always reveal edema, rings, exudates, furrows, and strictures and can be assessed using the EoE Endoscopic Reference Scoring system (EREFS).7 EREFS allows for systematic identification of abnormalities that can inform decisions regarding treatment efficacy and decisions on the need for esophageal dilation. When the esophageal mucosa is evaluated for biopsies, furrows and exudates should be targeted, if present, and multiple biopsies (minimum of five to six) should be taken throughout the esophagus given the patchy nature of the disease.