Eosinophillic esophagitis (EoE) is a disease in which the esophagus becomes inflamed due to large presence of a white blood cell called the eosinophil. The inflammation causes the esophagus to stiffen or narrow which leads to difficulties with swallowing or food getting stuck. Healthy people can have these white blood cells in other parts of the gastrointestinal tract, but their occurrence in the esophagus is an abnormal condition. Initially thought to be rare, EoE is now recognized as one of the most common causes of difficulty swallowing in young adults.