Eosinophilic esophagitis (EoE) is a chronic, allergic inflammatory disease of the esophagus. EoE affects children and adults. It occurs when a type of white blood cell, the eosinophil, accumulates in the esophagus. The elevated number of eosinophils causes injury and inflammation to the esophagus. Eventually leading to scar tissues. Adults with EoE usually present with difficulty swallowing. Many patient have other allergic diseases, such as seasonal allergies, asthma, allergic reactions to foods and environment.