Eosinophilic esophagitis (EoE) is a chronic, allergic inflammatory disease of the esophagus (the tube connecting the mouth to the stomach). It occurs when a type of white blood cell (eosinophil) builds up in the lining of the tube that connects your mouth to your stomach. This buildup then reacts to foods, allergens or acid reflux, and can then inflame or injure the esophageal tissue. Damaged esophageal tissue can lead to difficulty swallowing or can cause food to get stuck in your throat when swallowing.Eosinophilic esophagitis is a chronic immune system disease. It has been identified only in the past two decades but is now considered a major cause of digestive system (gastrointestinal) illness. Research is ongoing and is likely to lead to revisions in the diagnosis and treatment of eosinophilic esophagitis.