Eosinophilic esophagitis (EoE) is a Th2-mediated disease induced by ingestion of ambiental and alimentary allergens. Incidence of EoE is increasing in recent years. Young male subjects are more often affected by EoE. Esophageal eosinophilic infiltrate causes different symptoms of esophageal dysfunction (i.e. dysphagia, food impaction, chest pain, heartburn). In pediatric population symptoms are nonspecific (failure to thrive, vomiting) and more common to be misdiagnosed.

Symptoms are commonly sporadic and underestimated by the patients. Therefore, specialistic evaluations are often delayed during the following months and years. Moreover, esophageal symptoms are often not investigated or associated with other diseases especially in pediatric population (i.e. gastroesophageal reflux disease). For this reason, diagnosis of EoE is often delayed. It is known from literature that diagnostic delay in EoE causes prolonged inflammation of the esophagus that may lead to esophageal fibrosis and stenosis with worsening of symptoms. Proton pump inhibitors (PPIs) and topical steroids are the first line medicines to induce EoE remission. Prolonged clinical remission is described in 60% of adult patients with PPIs. Recently orodispersible budesonide showed clinical remission after 1 year nearby in 90% of adult patients. Orodispersible budesonide is effective also in chidren with an efficacy in maintaining remission at lowest effective dosage after 60 weeks in around 78% of patients. Dysphagia Symptom Questionnaire (DSQ) is a validated tool used in order to measure clinical activity (dysphagia) in adult and pediatric patients with EoE. Italian version of the DSQ is not available in literature. Little is known in literature about the natural history of EoE patients, in particular about sustained clinical remission and appearance of complications (i.e. food impaction) during a prolonged follow-up period. Aim of our two-phase prospective study is to evaluate the clinical and endoscopic response at the current available therapies and the appearance of complications during a prolonged follow-up period in a cohort of adult and pediatric population.

Two phases multicentre prospective observational study. In the first phase of the study, the Italian version of DSQ will be validated. In the second phase of the study, the clinical outcome of EoE patients will be investigated. Patients enrolled in the first phase will also enter in the second phase. For exploratory aim, serum and oesophageal tissue samples will be collected only in patient enrolled in S. C. General MedicineI.

Inclusion Criteria:

• patients with an established diagnosis of Eosinophilic esophagitis;
• aged ≥5 years;
• who gave written informed consent.

Exclusion Criteria:

• under 5 years old;
• Patients who are illiterate;
• Patients who are unwilling to participate

Eosinophilic esophagitis patients who will access to the Endoscopy unit or to the Clinic "Medicina Generale 1" and to the others involved Centers will be consecutively enrolled.