IGHE and eosinophilic esophagitis: We aimed to evaluate immunoglobulin G4 (IgG4) in eosinophilic esophagitis (EoE) and investigate the correlation among IgG4-positive plasma cells in esophageal tissue, total serum immunoglobulin E (IgE), specific IgE, and specific IgG4 (sIgG4) levels to six foods (milk, egg, wheat, soy, peanut, and seafood).<h4>Methods</h4>A retrospective observational study with prospective patient inclusion was conducted from 2017 to 2024 in a real-world setting.