title: The extremely narrow-caliber esophagus is a treatment-resistant subphenotype of eosinophilic esophagitis.
abstract: OBJECTIVE
  Some patients with eosinophilic esophagitis (EoE) have an extremely narrow esophagus, but the characteristics of this group have not been extensively described. We aimed to characterize the narrow-caliber phenotype of EoE, determine associated risk factors, and identify differences in treatment response in this subgroup of patients.
  
  
  METHODS
  This retrospective cohort study from 2001 to 2014 included subjects with a new diagnosis of EoE per consensus guidelines. Demographic, endoscopic, histologic, and treatment response data were extracted from medical records. An extremely narrow-caliber esophagus was defined when a neonatal endoscope was required to traverse the esophagus due to the inability to pass an adult endoscope. Patients with and without an extremely narrow-caliber esophagus were compared. Multivariable logistical regression was performed to assess treatment outcomes.
  
  
  RESULTS
  Of 513 patients with EoE, 46 (9%) had an extremely narrow-caliber esophagus. These patients were older (33 vs 22 years; P < .01), had longer symptom duration (11 vs 3 years; P < .01), more dysphagia (98% vs 66%; P < .01), and food impactions (53% vs 31%; P < .01). Dilation was more common with extreme narrowing (69% vs 17%; P < .01). Patients with a narrow-caliber esophagus were more refractory to steroid treatment, with lower symptom (56% vs 85%), endoscopic (52% vs 76%), and histologic (33% vs 63%) responses (P < .01 for all), and these differences persisted after multivariate analysis.
  
  
  CONCLUSIONS
  The extremely narrow-caliber esophagus is a more treatment-resistant subphenotype of EoE and is characterized by longer symptom duration and the need for multiple dilations. Recognition of an extremely narrow-caliber esophagus at diagnosis of EoE can provide important prognostic information.
authors.affiliation: Center for Esophageal Diseases and Swallowing, Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
authors.forename: Swathi
authors.initials: S
authors.lastname: Eluri
authors.affiliation: Center for Esophageal Diseases and Swallowing, Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Runge
authors.affiliation: Center for Esophageal Diseases and Swallowing, Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
authors.forename: Cary C
authors.initials: CC
authors.lastname: Cotton
authors.affiliation: Center for Esophageal Diseases and Swallowing, Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
authors.forename: Caitlin M
authors.initials: CM
authors.lastname: Burk
authors.affiliation: Center for Esophageal Diseases and Swallowing, Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
authors.forename: W Asher
authors.initials: WA
authors.lastname: Wolf
authors.affiliation: Department of Pathology and Laboratory Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
authors.forename: John T
authors.initials: JT
authors.lastname: Woosley
authors.affiliation: Center for Esophageal Diseases and Swallowing, Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA; Center for Gastrointestinal Biology and Disease, Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Shaheen
authors.affiliation: Center for Esophageal Diseases and Swallowing, Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA; Center for Gastrointestinal Biology and Disease, Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
authors.forename: Evan S
authors.initials: ES
authors.lastname: Dellon
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D003680:Deglutition Disorders / Q000188:drug therapy / Q000209:etiology / Q000473:pathology*; D057765:Eosinophilic Esophagitis / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D004940:Esophageal Stenosis / Q000209:etiology / Q000473:pathology*; D004947:Esophagus / Q000473:pathology*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009929:Organ Size; D011379:Prognosis; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones