Eosinophilic Esophagitis

Abstract

This chapter is about the primary, allergy-related eosinophilic conditions affecting the gut. The main focus is eosinophilic esophagitis; eosinophilic gastritis, eosinophilic gastroenteritis, and eosinophilic colitis are also mentioned. The term “eosinophilic gastrointestinal disease” (EGID) encompasses all of these entities. Eosinophilic esophagitis is uncommon, and the other EGIDs are rare, meaning that outside of the esophagus, nearly all examples of increased eosinophils in the gut tissue will be secondary to some other causes. The diagnosis of an EGID, therefore, depends on three criteria: increased tissue eosinophils, appropriate clinical symptoms, and exclusion of other conditions known to recruit eosinophils. Several questions arise: What is the definition of “increased eosinophils?" Should there be a marked increase before EGID is considered? What are the other conditions to be excluded, and are there histologic clues to those conditions? Consensus criteria are available for eosinophilic esophagitis and are reviewed here.