In eosinophilic esophagitis (e-o-sin-o-FILL-ik uh-sof-uh-JIE-tis), a type of white blood cell (eosinophil) builds up in the lining of the tube that connects your mouth to your stomach (esophagus). This buildup, which is a reaction to foods, allergens or acid reflux, can inflame or injure the esophageal tissue. Damaged esophageal tissue can lead to difficulty swallowing or cause food to get caught when you swallow.
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 will likely lead to revisions in its diagnosis and treatment.