Eosinophilic Esophagitis and Eosinophilic Gastroenteritis: Similarities and Differences

다국어 초록 (Multilingual Abstract)

Eosinophilic gastrointestinal disease (EGID), a chronic allergic condition characterized by dense infiltration of eosinophils in the digestive tract, is classified into two types, eosinophilic esophagitis (EoE), which features dense infiltration of eosinophils in the esophageal epithelial layer, and eosinophilic gastroenteritis (EGE), in which the entire digestive tract including the esophagus may be involved. Patients with EoE only have esophageal symptoms, since the other parts of the digestive tract are not involved. On the other hand, 80% of EGE patients have lesions in the small intestine. The esophageal epithelial layer in healthy individuals has no or negligible infiltration by eosinophils, while the small intestinal mucosal layer, especially the distal small intestinal mucosa, can show dense eosinophil infiltration even in the absence of disease. Therefore, histological changes observed in cases of EGE are not qualitative but rather quantitative, as compared to EoE, which has qualitative histopathological changes, indicating important pathogenetic differences between the types. Comparisons of clinical, laboratory, and morphological characteristics between EoE and EGE have revealed several interesting differences. Both EoE and EGE patients are frequently affected by atopic diseases, such as bronchial asthma and allergic rhinitis, and elevated plasma levels of Th2 type cytokines and chemokines are also similarly seen in both. On the other hand, age at diagnosis differs, as the former is generally found in individuals from 30 to 50 years old, while the latter appears in all age groups. Additionally, 80% of patients with EoE are male as compared to only 50% of those with EGE. Furthermore, approximately 60% of patients with EoE respond favorably to proton pump inhibitor (PPI) administration, whereas EGE patients rarely show a response to PPIs. Nevertheless, both diseases show a similarly favorable response to a six foods elimination diet and glucocorticoid administration. These similarities and differences of EoE and EGE provide important clues for understanding the pathogenesis of these EGID types.