Diagnosis and treatment of eosinophilic esophagitis in clinical practice.

Eosinophilic esophagitis (EoE) is a chronic and abnormal Th2 type immunological response characterized by intense eosinophilic inflammation localized within the esophagus. This leads to esophageal dysfunction and remodeling accompanied by subepithelial fibrosis. Recently, EoE has been recognized as one of the major causes of dysphagia or food impaction in adults. The prevalence of EoE has been increasing over the past several decades, particularly in Western countries. EoE should be differentiated from secondary esophageal eosinophilia (EE) in gastroesophageal reflux disease (GERD) and eosinophilic gastroenteritis, involving the entire gastrointestinal tract. EoE is an uncommon condition in Asia compared with Western countries. With the growing interest and awareness of this condition during the past decade, reports of this disease are increasingly emerging in Asian countries including Japan. Typical EoE does not respond to proton pump inhibitor (PPI) therapy according to the current Western diagnostic guidelines. However, some cases of EE exhibit symptomatic relief and histological improvement in response to PPI [i.e., PPI-responsive esophageal eosinophilia (PPI-REE)]. The understanding of the clinical manifestations and unique endoscopic images of EoE, differences and similarities between GERD, PPI-REE, and EoE will all serve as the differential diagnosis. Further knowledge of the indications and efficacy of PPI therapy and topical steroid therapy will also aid in the management of these diseases. In this article, we will review the current diagnosis and treatment of EoE in clinical practice.