['Gastro-oesophageal reflux has been suggested to play a role in eosinophilic oesophagitis (EoO). Oesophageal acid exposure decreases baseline intraluminal impedance, a marker of mucosal integrity, in patients with gastro-oesophageal reflux disease (GORD).', 'The aim of this study was to assess oesophageal baseline impedance levels in EoO patients and to investigate their relationship with oesophageal acid exposure.', 'Ambulatory 24-h pH-impedance monitoring was performed in 11 EoO patients and in 11 healthy controls with matched oesophageal acid exposure. We assessed baseline impedance levels in the distal, mid-, and proximal oesophageal impedance channels.', 'BASELINE IMPEDANCE LEVELS IN EOO PATIENTS WERE MARKEDLY LOWER COMPARED TO CONTROLS IN THE DISTAL OESOPHAGUS (MEDIAN (INTERQUARTILE RANGE): 988 (757-1978) vs. 2259 (1767-2896) Ω, p\u2009=\u20090.015), mid-oesophagus (1420 (836-2164) vs. 2614 (2374-3879) Ω, p\u2009=\u20090.003), and proximal oesophagus (1856 (1006-2625) vs. 2868 (2397-3439) Ω, p\u2009=\u20090.005). Whereas baseline impedance decreased from proximal to distal in healthy subjects (p\u2009=\u20090.037), no such gradient was seen in EoO patients (p\u2009=\u20090.123).'] Are oesophageal baseline impedance values decreased in patients with eosinophilic oesophagitis?