Is Asymptomatic Esophageal Eosinophilia the Same Disease Entity as Eosinophilic Esophagitis?

Eosinophilic esophagitis (EoE) is an allergic inflammatory disorder that is characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation. Its prevalence has been increasing rapidly in both Western and Asian countries. In Japan, most of the cases of esophageal eosinophilia (EE) are found in an upper endoscopy examination for gastric cancer screening performed during a comprehensive health check-up. Indeed, we frequently encounter patients with asymptomatic EE showing typical endoscopic findings, such as linear furrows, as well as histologic findings compatible with EoE. However, the current clinical guidelines for EoE diagnosis include symptoms related to esophageal dysfunction, thus patients without symptoms do not fulfill the diagnostic criteria. The clinical characteristics remain to be fully elucidated, thus we aimed to clarify clinical features of asymptomatic EE as compared with those of EoE.