SummaryBackgroundCurrent diagnostic guidelines recommend that eosinophilic oesophagitis (EoE) should be diagnosed only after GERD is excluded by a lack of response to a trial of acid suppression. There is limited information available providing outcome data about the effectiveness of this approach.AimTo examine the impact of double‐dose proton pump inhibitor (PPI) therapy on symptoms, endoscopic and histological features in patients with documented oesophageal eosinophilia consistent with EoE (≥15 eosinophils/high‐power field).MethodsSixty consecutive symptomatic patients with documented oesophageal eosinophilia received open‐label omeprazole 20 mg orally twice daily before meals for 8 weeks. Clinical, endoscopic and histological (resolution: 0–5 eosinophils/HPF, partial improvement: 5–14 eosinophils/HPF), or no improvement: (≥15 eosinophils/HPF) evaluation was repeated at the end of this period. An expert GI pathologist, unaware of the study aims, reviewed all slides.ResultsClinical improvement occurred in 43 (71.6%), endoscopic signs were reduced in 34 (61.8%) and normalised in 12 (21.8%), and histologically, 34 (56.6%) improved, while 15 (25%) obtained complete resolution. Overall, 22 patients (36.7%) obtained both complete clinical and histological remission.ConclusionsMore than 50% of patients with documented oesophageal eosinophilic infiltration in the EoE range improved when treated with a double‐dose PPI trial for 8 weeks. These findings support the published guidelines recommending a PPI trial prior to diagnosing EoE, and confirm the existence of an eosinophilic oesophageal infiltrationPPI‐responsive population.