- Subject is having a clinically indicated endoscopy for suspicious EoE and has been on BID PPI for at least 8 weeks OR New diagnosis of EoE as per consensus guidelines. Cases must have symptoms of dysphagia, persistent esophageal eosinophilia (≥ 15 eosinophils in at least one high-power field) after 8 weeks of treatment with a twice daily proton-pump inhibitor, and other competing causes of esophageal eosinophilia excluded.