Food-related reactions in eosinophilic esophagitis: pathophysiology and treatment

Eosinophilic esophagitis (EoE) is a chronic, food-mediated type 2 (T2) inflammatory disease of the esophagus. Elimination of dietary triggers, particularly cow's milk, results in considerable rates of both histological and clinical disease remission. A growing body of evidence supports the role of food allergens in initiating and maintaining esophageal inflammation, either through direct disruption of the epithelial barrier or via interaction with antigen-presenting cells in the subepithelial tissue. Importantly, EoE is not a classical IgE-mediated food allergy, and conventional allergy tests have a poor predictive value in guiding dietary interventions. While IgG4 antibodies have been implicated in the disease process, their role remains unclear and may reflect a bystander phenomenon rather than a causal mechanism. Recently, a novel food-induced immediate reaction of the esophagus (FIRE) has been described in EoE patients. This reaction involves rapid onset esophageal symptoms following ingestion of specific food allergens and bears resemblance to the oral allergy syndrome. Finally, a direct effect of food allergens has been shown in experimental procedures using injection of allergens into the esophageal mucosa and in vitro by stimulating freshly collected esophageal biopsies. The following review summarizes the up-to-date knowledge about food reactions in EoE.