**12.1 PPI**

PPI is now used as the first-line treatment of EoE. In adults patients treated with PPI, symptomatic improvement can range from 25–80% and histological remission from 33–61% [33]. As mentioned before, PPI can block IL-4 stimulated eotaxin-3 secretion and thus can inhibit eosinophil recruitment from blood into the esophageal tissue [34]. Significant improvement of dysphagia can occur in few days' time. PPI can also be used as an adjunctive therapy when patients with EoE require esophageal dilation. Richter et al. found that esophageal eosinophilia was decreased in patients who received combination of PPI and esophageal dilation but not in patients who had esophageal dilation alone [35]. Finally, PPI can also restore the esophageal mucosal barrier function in patients with EoE and thus can inhibit the entry of aeroallergens into the esophageal mucosa [36]. It is author's opinion that in endotype 1, full dose of PPI once a day or low dose PPI twice a day should be initiated. Patients should be evaluated for symptomatic/clinical response after 4 weeks. At that time, there will be 2 groups:


A recent study found that in endotype 2, continuation of PPI therapy for at least 12 weeks had greater chance of inducing remission of EoE whereas in endotype 3, there was less responsiveness to PPI therapy both in the beginning and in the long run [37].
