Eosinophilic Esophagitis: Interactions with Gastroesophageal Reflux Disease

Eosinophilic esophagitis is a chronic immune/antigen-mediated esophageal disease characterized by the presence of symptoms of esophageal dysfunction, primarily dysphagia in adults, combined with histological evidence of eosinophil-predominant inflammation. The histopathological findings of increased esophageal eosinophilia are not specific for eosinophilic esophagitis and have been described in a number of infectious and inflammatory esophageal disorders. Moreover, there is significant overlap in the symptoms and histology between eosinophilic esophagitis and gastroesophageal reflux disease. The relationship between eosinophilic esophagitis and gastroesophageal reflux disease has been the source of recent investigation. Proton pump inhibition may reverse elevated esophageal eosinophilia in a subset of patients suspected of having eosinophilic esophagitis, even in the absence of other objective evidence of gastroesophageal reflux disease (erosive esophagitis, abnormal pH testing). It is unclear at this time whether the response to PPI is truly diagnostic for gastroesophageal reflux disease or perhaps indicative of a proton pump inhibitor-responsive form of eosinophilic esophagitis. In this chapter, the challenges in diagnosing eosinophilic esophagitis and the difficulties in distinguishing it from gastroesophageal reflux disease are reviewed.