The current project aims to improve the care for children and adolescents with eosinophilic esophagitis in a collaborative effort involving pediatric units at Oslo Unversity Hospital and Helse Bergen, Norway. Existing and new non-invasive biomarkers will be explored systematically, aiming to reduce the number of endoscopies and time on restricted diet.

The overall aim of the current proposal is to improve the care for children and adolescents with EoE and reduce the need for complex elimination diets and repeated endoscopies.

Our objectives are to determine whether

1. at diagnosis the following are predictive for response to food elimination:

   1. history of atopy, symptoms after food intake
   2. eosinophil counts in biopsies and peripheral blood
   3. total IgE, specific IgE, eosinophilic granula proteins, eosinophil progenitor cells in blood
   4. key cytokines (Eotaxin-3, IL-5, IL-13)
   5. eosinophil derived neurotoxin/EDN in oesophageal aspirates, blood samples and feces
   6. circulating microRNAs

2. at follow-up biomarkers collected by non-invasive methods can predict endoscopic and histologic healing

   1. eosinophil counts in esophageal brushes and peripheral blood
   2. total IgE, specific IgE, eosinophilic granula protein, eosinophil progenitor cells
   3. circulating cytokines like eotaxin-3, IL-5, IL-13
   4. eosinophil derived neurotoxin/EDN in esophageal brushes, blood samples and feces
   5. circulating microRNAs

Inclusion Criteria:

• a diagnosis of eosinophilic esophagitis
• suspected but not yet confirmed eosinophilic esophagitis

Exclusion Criteria:

• chronic severe conditions that preclude general anaestesia
• lack of consent

Children with newly diagnosed or previously confirmed eosinophilic esophagitis.

Not planned due to confidentiality