Localized esophageal eosinophilia: Is it an early manifestation of eosinophilic esophagitis or a subtype of gastroesophageal reflux disease?

Background and Aim We recently encountered patients with localized esophageal eosinophilia in a small area of the esophagus. However, this condition remains to be described in detail, and its clinical significance has not been established. We investigated the clinical, endoscopic and histological features of localized esophageal eosinophilia in comparison with diffuse esophageal eosinophilia. Methods We investigated 10 patients with localized esophageal eosinophilia, and compared them with 23 who had diffuse esophageal eosinophilia. Whether esophageal eosinophilia was localized or diffuse was determined on the basis of endoscopic findings. Localized esophageal eosinophilia was defined endoscopically as a focal area of esophageal eosinophilia, whereas diffuse esophageal eosinophilia was defined as a widespread area of esophageal eosinophilia involving more than one of three locations: the upper, middle and lower esophagus. Histological esophageal eosinophilia in the mucosa showing endoscopic abnormality was confirmed by biopsy with a peak of ≥15eosinophils/high-power field. Results There were no significant differences in age, gender distribution, allergic conditions or peripheral eosinophilia between the two groups. In all cases but one, localized esophageal eosinophilia was observed in a small area above the esophagogastric junction. Esophageal symptoms such as dysphagia, heartburn or chest pain were present in 20% of the localized group and in 65% of the diffuse group, the difference being statistically significant (P<0.05). The maximum amounts of eosinophils infiltrating the esophageal mucosa did not differ between the groups. Conclusions Esophageal eosinophilia can be localized in a small area, especially above the esophagogastric junction. Gastric acid reflux or contact may influence this condition in addition to its allergic pathogenesis.