Eosinophilic esophagitis (EoE) is recognized as a common, allergy-associated cause of chronic esophageal symptoms affecting both children and adults. Research has begun to shed light on its epidemiology with consistent results from various geographical areas. Differences in clinical presentation, endoscopic aspects and response to treatment have all been reported for patients of different ages, and the question as to whether adult and pediatric EoE are manifestations of a single entity or in fact two distinct disorders has been posed. The most relevant differences between pediatric and adult EoE come from evolutionary changes in the consequences of the disease, including fibrous remodeling, and the ability to express symptoms. However, most studies support a common pathogenesis and similar histopathological features for adult and pediatric patients, being the same diagnostic criteria applied to them. This article comprehensively reviews the most recently published information and addresses important questions about the natural history of EoE.