Endoscopic abnormalities in patients with EoE include fixed esophageal ring which is corrugated, white exudates or plaques, longitudinal furrows, mucosal pallor, diffuse esophageal narrowing, mucosal fragility leading to esophageal lacerations during the endoscopy.

• Mucosal biopsies of the esophagus should be obtained in all patients in whom EoE is a clinical possibility regardless of the endoscopic appearance.
• Endoscopic abnormalities in patients with EoE are as follows:^{[1][2][3][4][5]}
  • Fixed esophageal ring which is corrugated
  • White exudate
  • Longitudinal furrows
  • Mucosal pallor
  • Diffuse esophageal narrowing
  • Mucosal fragility leading to esophageal lacerations during the endoscopy
• However, because these endoscopic features have been described in other esophageal disorders, none can be considered pathognomonic for EoE.

• 
  Endoscopy of the esophagus: Eosinophilic esophagitis
  Source: Wikimedia

• Characteristic features are as follows:
  • > 20 eosinophils/0.24 mm2.
  • Papillae are elongated
  • Papillae reach into the top 1/3 of the epithelial layer
  • Basal cell hyperplasia; > 3 cells thick or >15% of epithelial thickness