Abstract
Eosinophilic esophagitis (EoE) is a chronic inflammatory condition that is characterized by dense eosinophilic infiltration in the esophageal mucosa, which leads to esophageal dysfunction and stricture. It has been proposed that an abnormal immunological reaction, localized in the esophagus, against any food and/or inhaled antigen participates pivotally in this condition, but the pathological mechanism is largely unknown. The incidence of EoE has recently been increasing in Western countries and EoE is noted as a major cause of dysphagia and food impaction. The basis for the diagnosis is clinical symptoms related to esophageal dysfunction and histopathological findings, and in addition secondary causes of esophageal eosinophilia need to be excluded. In particular, to discriminate from GERD, unresponsiveness to PPI therapy is essential for the diagnosis of EoE in the updated clinical diagnostic guidelines of Western countries. Patients with EoE have several characteristic endoscopic findings, and the recognition of these findings is an important clue in the diagnosis of this disease. In this chapter, in addition to presenting the updated clinical guidelines in Western countries and Japan, we describe the points and pitfalls in the diagnosis of EoE, especially with regard to endoscopic findings and histopathological findings.
