Eosinophilic esophagitis (EoE) is a major cause of dysphagia and food impaction. Recognition and diagnosis of EoE have been increasing rapidly, but the role of proton pump inhibitors (PPIs) for the diagnosis of EoE and treatment of esophageal eosinophilia remains controversial. Initial diagnostic algorithms for EoE relied on a PPI trial to distinguish EoE from gastroesopha-geal reflux disease, a common cause of esophageal eosinophilia. This approach has become complicated by the recent recognition of PPI-responsive esophageal eosinophilia (PPI-REE), a disorder characterized by clinicopathologic features similar to EoE but that resolve with high-dose PPI therapy. The mechanism of PPI action for treatment of esophageal eosinophilia may rely not only on acid suppression but also on novel anti-inflammatory effects of the PPIs themselves. Treatment with PPI therapy is now considered a required step before a formal diagnosis of EoE can be made, and continuing PPI therapy in patients with PPI-REE is a common strategy. However, the role of continuing PPI monotherapy in patients with EoE remains a matter of debate. The decision to do so should hinge on improvement in symptoms and histology as well as the need for ongoing dilation.
Keywords: Eosinophilic esophagitis; gastroesophageal reflux disease; proton pump inhibitor; proton pump inhibitor—responsive esophageal eosinophilia.