title: Acid hypersensitivity in patients with eosinophilic oesophagitis.
abstract: OBJECTIVE
  Painful symptoms are prevalent in patients with eosinophilic oesophagitis but experimental data are sparse. The aim of this study was to compare the pain response to experimental oesophageal stimulation in 14 patients with eosinophilic oesophagitis and 15 healthy volunteers.
  
  
  METHODS
  A multimodal probe was placed in the oesophagus. The participants were subjected to mechanical, thermal and electrical pain stimuli followed by perfusion with 0.1 M HCl. Pain scores, referred pain areas and evoked brain potentials to electrical stimulation of the oesophagus were recorded.
  
  
  RESULTS
  Patients tolerated significantly less acid perfused in the oesophagus (median 123 versus 200 ml; P = 0.02) and felt the burning sensation evoked by the acid earlier (median 2.0 versus 5.0 min; P = 0.01). Eight patients had coexisting gastro-oesophageal reflux disease. Six patients had pure eosinophilic oesophagitis, and this group felt the acid earlier than those with concomitant reflux or the healthy volunteers (median 0.8 versus 2.0 and 5.0 min; P = 0.03). There were no differences between patients and controls in the responses to mechanical or thermal stimulation (P > 0.4). Furthermore, no differences were found for the proxies of central nervous system sensitization (response to electrical stimulations, referred pain areas or evoked brain potentials; P > 0.1).
  
  
  CONCLUSIONS
  Patients with eosinophilic oesophagitis are hypersensitive to acid perfused in the oesophagus, and pathophysiologic findings are likely confined to the peripheral tissue. Reflux from physiological acid may play a role in the symptoms of eosinophilic oesophagitis.
authors.affiliation: Mech-Sense, Department of Gastroenterology, Aalborg Hospital, Aarhus University, Aalborg, Denmark.
authors.forename: Anne Lund
authors.initials: AL
authors.lastname: Krarup
authors.forename: Gerda Elisabeth
authors.initials: GE
authors.lastname: Villadsen
authors.forename: Else
authors.initials: E
authors.lastname: Mejlgaard
authors.forename: Søren Schou
authors.initials: SS
authors.lastname: Olesen
authors.forename: Asbjørn Mohr
authors.initials: AM
authors.lastname: Drewes
authors.forename: Peter
authors.initials: P
authors.lastname: Funch-Jensen
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D004941:Esophagitis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006851:Hydrochloric Acid / Q000009:adverse effects*; D006930:Hyperalgesia / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology* / Q000503:physiopathology*; D010147:Pain Measurement
chemical_list: D006851:Hydrochloric Acid