Eosinophilic esophagitis that develops during therapy with proton pump inhibitors : case series and possible mechanisms

Therapy with proton-pump inhibitors (PPIs) results in remis- sion in at least one third of patients with esophageal eosinophilia, presumably because of both their acid-related and anti-inflamma- tory mechanisms of action. However, eosinophilic esophagitis (Eoe) may also develop during therapy with PPIs. We present a case series of four children who were initially diagnosed with infec- tious esophagitis, gastroesophageal reflux disease or gastric ulcer, who had no eosinophilic infiltration of the esophagus, but subse- quently developed symptoms, endoscopic features and histological picture of typical Eoe. We discuss mechanisms of action of PPIs of likely relevance to an increased risk of development of Eoe in some patients , such as their influence on mucosal barrier function, inter- ference with pH-related protein digestion by pepsin, and antigen processing by immune cells. (Acta gastroenterol. belg., 2016, 79, 245- 250).