The Potential Link Between Eosinophilic Esophagitis and Food Allergy: Inflammatory Pathogenesis and Management

Eosinophilic esophagitis (EoE) has transitioned from an isolated gastrointestinal disorder to a recognized type 2 immune-mediated allergic disease, most likely representing a late manifestation of the atopic march. This comprehensive review examines the complex inflammatory pathogenesis linking EoE and food allergy, and critically discusses the mechanisms of disease induction, dietary treatments, and emerging clinical challenges. While genome-wide association studies identify shared susceptibility loci with classic atopy, EoE exhibits distinct tissue-specific pathways, particularly dominated by the local interleukin (IL)-13 axis and highly esophagus-selective proteases like Calpain-14. This unique immunological interplay is clinically epitomized by food oral immunotherapy (OIT)-induced EoE. During OIT, systemic immune reprogramming successfully drives immune tolerance-marked by a robust increase in plasma food-specific IgG4-but fails at the local level, due to the persistence of pathogenic Th2 cells and aberrant mucosal IgG4 immune complex deposition within the esophageal lamina propria. Regarding therapeutic management, conventional skin and serum allergy testing remain highly inaccurate in identifying dietary triggers, rendering test-guided diets ineffective. Conversely, empiric elimination diets achieve robust histological remission, ranging from standardized six-food restrictions to pragmatic single-food approaches targeting cow's milk. Furthermore, novel insights into industrial milk processing (such as UHT sterilization and homogenization) and specific beta-casein genetic variants (A1 vs A2) highlight how altered protein structures generate neoantigens that accelerate esophageal immunogenicity. In conclusion, decoding the divergent immunological mechanisms operating in the refractory esophagus is essential to move beyond trial-and-error dietary interventions towards non-invasive monitoring tools, precision medicine, and optimized biological therapies in EoE management.