1. Registry of demographic, clinical, endoscopic and histological data at baseline.

2. Registry of patients treated with PPI:

   • Clinical, endoscopic and histological response at 8-12 weeks of induction treatment
   • Clinical, endoscopic and histological response at 6 and 12 months weeks of maintenance treatment

3. Registry of patients treated with two foods elimination diet:

   • Clinical, endoscopic and histological response at 8-12 weeks of induction treatment
   • Identification of food trigger: milk, gluten or milk and gluten
   • Clinical, endoscopic and histological response at one year elimination of food trigger
   • Registry of adverse events

4. Registry of patients treated with swallowed steroids (budesonide or fluticasone):

   • Clinical, endoscopic and histological response at 8-12 weeks of induction treatment
   • Clinical, endoscopic and histological response at 6 months of maintenance steroid treatment
   • Registry of adverse events

Inclusion Criteria:

• Children from 1 month to 18 years with a new diagnosis of eosinophilic esophagitis (EoE) according to the recent European guidelines (symptoms of esophageal dysfunction + eosinophilic infiltrate of the esophagus > 15 eos / CGA)
• And that they need to start treatment with any of the following options: PPI, diet excluding cow's milk and gluten, or swallowed corticosteroids .

Exclusion Criteria:

• Presence of pathological eosinophilia at the gastric or duodenal level (eosinophilic gastroenteritis)
• Simultaneous treatment with more than one treatment modality (PPI, empirical elimination diet, swallowed corticosteroids).

Children from 1 month to 18 years with a new diagnosis of eosinophilic esophagitis according to the recent European guidelines