Diagnosis of eosinophilic esophagitis: current approach and future directions

Eosinophilic esophagitis (EoE), a chronic inflammatory condition with a rapidly evolving epidemiology, is now a major cause of esophageal disease. Current guidelines emphasize that EoE is a clinicopathologic condition with the following criteria: clinical symptoms of esophageal dysfunction; at least 15 eosinophils in one high-power field on esophageal biopsy; and lack of responsiveness to high-dose proton-pump inhibition or normal pH monitoring of the distal esophagus. Challenges in diagnosis include lack of standardized esophageal biopsy protocols, variability in how eosinophil counts are determined, variability in the size of microscope high-power fields, and the need to evaluate the differential diagnosis of esophageal eosinophilia. In particular, the complex interplay between esophageal eosinophilia, EoE, and reflux disease remains an area both of controversy and active study. In the future, diagnostic strategies could include symptom scores, tissue or noninvasive biomarkers, and/or genetic expression profiles.