Inclusion Criteria:  -Patients with an established diagnosis of EoE, based on endoscopy with biopsies with ≥15 eosinophils per hpf in esophageal biopsies after symptoms of esophageal dysfunction persist despite at least 6-8 weeks of appropriate acid suppression therapy.  OR  -Patients who are suspected of having EoE (presenting with symptoms of esophageal dysfunction non-responsive to appropriate proton pump inhibitor therapy for 6-8 weeks).  • Note: Patients suspected of having EoE but not diagnosed with EoE by endoscopy with biopsies will serve as control patients  Exclusion Criteria:  Patients who do not consent to participate