Eosinophilic esophagitis investigated by upper gastrointestinal endoscopy in Japanese patients.

Background: The prevalence of eosinophilic esophagitis (EE) is increasing rapidly in Western countries. Several case series of EE have also been reported in Japan. However, the prevalence of EE in Japanese patients as investigated by upper gastrointestinal endoscopy is unknown. Therefore, we carried out a prospective multicenter study to address this issue.

Methods: From July to December 2010, 23,346 patients who had undergone routine upper gastrointestinal endoscopy in 17 institutions were enrolled. In patients with symptoms suggesting EE, such as dysphasia, food impaction, and heartburn, and/or in patients in whom endoscopic findings suggested pathology, esophageal biopsy samples were collected, and the numbers of eosinophils in the squamous epithelium were counted.

Results: During the study period of 6 months, 4 patients were endoscopically and histologically diagnosed with EE. The prevalence of EE was calculated to be 17.1/100,000.

Conclusion: The prevalence of EE in Japanese patients by upper gastrointestinal endoscopy has now been documented.