From esophagus to colon: A narrative review of eosinophilic gastrointestinal disorders

Eosinophilic gastrointestinal disorders (EGID) are a heterogeneous group of chronic diseases characterized by excessive infiltration of eosinophils in the gastrointestinal tract in the absence of identifiable secondary causes. Primary EGID includes eosinophilic esophagitis, eosinophilic gastroenteritis, and eosinophilic colitis. The purpose of this review is to provide a concise overview of the current understanding and management of EGID. The published data were extracted by a comprehensive literature search in PubMed/MEDLINE with keywords related to EGID. The retrieved data were analyzed and synthesized into a narrative review emphasizing clinical features, evaluation, and treatment strategies. A brief outline of the etiopathogenesis of the disease was also derived from the published literature. EGID, especially esophagitis, has demonstrated an increasing global prevalence, more frequent in men and those with other atopic conditions. The etiology of EGID remains poorly understood, though allergic mechanisms are heavily implicated. Sensitization to foods or aeroallergens is common, yet only a minority experiences food-induced anaphylaxis, suggesting distinct non-IgE-mediated pathways in disease pathogenesis. Genetic factors and dysregulation in gene expression related to eosinophil recruitment, notably eotaxin-3, are implicated as well. The clinical manifestations vary according to the site of gastrointestinal tract involvement. The diagnosis relies on endoscopic biopsies to reveal the tissue eosinophilia. The treatment strategies include dietary modification or elimination diets, steroids and other anti-allergic medications, proton pump inhibitors, and monoclonal antibodies targeting eosinophils or key inflammatory cytokines. Therapeutic endoscopic procedures might benefit patients with strictures, particularly those involving esophagus.