distal and proximal esophagus (peak value of ≥ 15 eosinophils per high-power field (eos /HPF)), eosinophilia that is isolated to the esophagus and persists after a PPI trial, exclusion of secondary causes of esophageal eosinophilia, and a response to therapy [4]. In this review we focus on epidemiology, pathogenesis, clinical and histopathologic findings, and treatment for EoE.