[Recent progress in the research of Eosinophilic GastroIntestinal Diseases (EGIDs)]

Eosinophilic esophagitis (EoE) and eosinophilic gastroenteritis (EGE), which are included in eosinophilic gastrointestinal disorders (EGIDs), are allergic gastrointestinal diseases mainly caused by food allergens, which features dense infiltration of eosinophiles in the gastrointestinal mucosa. A possible mechanism of these diseases are Th2 type allergic reactions, including IL-5, IL-13, and IL-15, thymic stromal protein (TSLP), and eotaxin 3, which are considered to have important roles. The number of patients with EoE is rapidly increasing in both Western and Asian countries. In Japan, a research group of the Ministry of Health, Labor and Welfare has announced recommendations for the diagnosis and management of EoE and EGE in 2015. For a diagnosis of EoE, endoscopic abnormalities and histological confirmation of dense eosinophile infiltration in the esophageal epithelial layer are important, in addition to identifying dysphagia symptoms. As for eosinophilic gastroenteritis, blood test findings are more useful and the role of an endoscopic examination is reduced. Glucocorticoid administration is standard treatment for these diseases, while proton pump inhibitors are frequently effective for EoE. As for EoE, on the one hand, a variety of studies have been performed and new findings collected. On the other hand, information concerning EGE is limited and additional evidence is needed to establish effective treatment options.