The role of endoscopy in eosinophilic esophagitis: from diagnosis to therapy.

Endoscopy plays an important role in the management of eosinophilic esophagitis (EoE), since it is involved in the diagnosis, follow up and treatment of this condition. In patients presenting with food impaction, dysphagia and other symptoms of suspected EoE, esophago-gastric-duodenoscopy (EGD) with multiple esophageal biopsies should be performed to confirm or rule out the diagnosis of EoE. The EREFS system, a validated instrument for assessment of the endoscopically-identified esophageal features in EoE (edema, rings, exudates, longitudinal furrows and strictures), is currently used in the clinical practice for the evaluation of the macroscopic aspects of esophageal mucosa during EGD. Multiple esophageal biopsies are mandatory to further confirm EoE diagnosis and subsequent response to treatement, since symptoms reported by patients do not always correlate with histological activity, and considering the low sensitivity of endoscopic assessment; a cut-off of ≥ 15 eosinophils in at least one high power field is the density threshold considered the standard for diagnosis (sensitivity 100%, specificity 96%). Other histological features, included in the EoE histologic scoring system (EoEHSS), are supportive for the diagnosis and for the assessment of inflammatory activity during follow-up. Esophageal dilation, performed either with Savary dilators/bougie or hydrostatic baloon, is an effective and safe treatment in both adult and pediatric EoE patients with fibrostenotic features, mainly in association with other therapeutic strategies which can control eosinophilic inflammation.