Eosinophilic oesophagitis and proton pump inhibitor-responsive oesophageal eosinophilia have similar clinical, endoscopic and histological findings

Background Some patients with a phenotypic appearance of eosinophilic oesophagitis (EoE) respond histologically to PPI, and are described as having PPI-responsive oesophageal eosinophilia (PPI-REE). It is unclear if PPI-REE is a GERD-related phenomenon, a subtype of EoE, or a completely unique entity. Aim To compare demographic, clinical and histological features of EoE and PPI-REE. Methods Two databases were reviewed from the Walter Reed and Swiss EoE databases. Patients were stratified into two groups, EoE and PPI-REE, based on recent EoE consensus guidelines. Response to PPI was defined as achieving less than 15eos/hpf and a 50% decrease from baseline following at least a 6-week course of treatment. Results One hundred and three patients were identified (63 EoE and 40 PPI-REE; mean age 40.2years, 75% male and 89% Caucasian). The two cohorts had similar dysphagia (97% vs. 100%, P=0.520), food impaction (43% vs. 35%, P=0.536), and heartburn (33% vs. 32%, P=1.000) and a similar duration of symptoms (6.0years vs. 5.8years, P=0.850). Endoscopic features were also similar between EoE and PPI-REE; rings (68% vs. 68%, P=1.000), furrows (70% vs. 70%, P=1.000), plaques (19% vs. 10%, P=0.272), strictures (49% vs. 30%, P=0.066). EoE and PPI-REE were similar in the number of proximal (39eos/hpf vs. 38eos/hpf, P=0.919) and distal eosinophils (50 vs. 43eos/hpf, P=0.285). Conclusions EoE and PPI-responsive oesophageal eosinophilia are similar in clinical, histological and endoscopic features and therefore are indistinguishable without a PPI trial. Further studies are needed to determine why a subset of patients with oesophageal eosinophilia respond to PPI.