Epidemiology of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is an allergy-associated disease defined clinically by esophagus-related symptoms in combination with a dense esophageal eosinophilia, both of which are unresponsive to prolonged acid suppression with proton pump inhibitors. Over the last two decades EoE has increasingly been recognized in various geographical areas (mostly industrialized countries) with high socioeconomic development. The prevalence rate is increasing and reaches up to 50 patients per 100,000 inhabitants in some indicator regions. Whether this increased prevalence is due to a real increase in incidence, a result of increased awareness by health care providers or because of the nonfatal nature of EoE adding more and more cases to the patient pool is still a matter of controversy. Several studies have consistently demonstrated a male predominance in EoE, with a male-to-female risk ratio of 3:1. The average age at diagnosis ranges between 30 and 50 years and suggests that EoE is a disease of the middle-aged man. It can affect patients of every race, but the disease is more common among Caucasians. In both children and adults, EoE has been clearly associated with allergies to food and aeroallergens, and most EoE patients present with a personal allergic background (e.g. asthma, rhinoconjunctivitis or oral allergy syndrome). In conclusion, knowledge of epidemiologic parameters of EoE is crucial for identifying risk factors as well as pathogenic mechanisms, planning preventive measures and determining optimal treatment strategies.