Eosinophilic oesophagitis: pathophysiology, diagnosis, and treatment

Eosinophilic oesophagitis is a chronic, immune mediated condition characterised by infiltration of eosinophils across the oesophageal mucosa and progressive oesophageal dysfunction. This specialist review explores the changes in understanding of eosinophilic oesophagitis across epidemiology, pathophysiology, diagnosis, and treatment. It highlights the interplay of genetic susceptibility, early life environmental exposures, and immune responses driven by type 2 helper T cells that underpin epithelial barrier dysfunction and fibrostenotic progression. Current diagnostic strategies rely on endoscopic biopsy, but emerging minimally invasive tests (including the oesophageal string test and transnasal endoscopy) offer promising alternatives for disease monitoring. Therapeutic approaches include dietary elimination, drug treatments (eg, proton pump inhibitors, topical corticosteroids), biologics (particularly dupilumab), and endoscopic dilation for fibrostenotic complications. Evidence from landmark trials and guidelines to support phenotype driven, patient centred management are also reviewed. As eosinophilic oesophagitis prevalence continues to rise globally, recent advances in targeted treatments and diagnostics are redefining long term care.