Epidemiology, Natural History, and Treatment of Eosinophilic Gastrointestinal Diseases

Eosinophilic gastrointestinal diseases (EGIDs) are chronic inflammatory diseases driven by eosinophil-predominant pathologic infiltration in the gastrointestinal tract. The nomenclature system divides EGIDs into eosinophilic esophagitis (EoE) and non-EoE EGIDs based on whether the inflammation is restricted to the esophagus or involves other gastrointestinal segments. EGIDs are rapidly becoming a focus in gastroenterology due to a continuous increase in incidence and prevalence rates during the past 30 years and no plateau observed to date, particularly for EoE. The evolving epidemiology of EGIDs has been associated with numerous early life and environmental risk factors. The understanding of the natural history of EGIDs has also matured in recent years, with identification of a progression from inflammation to remodelling with fibrosis in EoE and recognition of mucosal, muscle layer, and serosal involvement with a continuous, progressive, or relapsing/remitting course in non-EoE EGIDs. The landscape of pharmacologic treatment for EGIDs has also expanded considerably. Proton pump inhibitors, swallowed topical corticosteroids, elimination diets, and dupilumab are currently recommended for EoE. Systemic or topical corticosteroids, elimination diets, proton pump inhibitors, and some biologic agents have shown efficacy in non-EoE EGIDs, mainly in observational studies, and several novel agents designed for EGIDs are under investigation. The present review discusses recent advances in the epidemiology, natural history, and risk factors of EoE and non-EoE EGIDs. The review also presents an update of treatment strategies according to the latest clinical guidelines and provides an overview of knowledge gaps to inform future research directions.