Atypical presentation of Olmesartan-induced gastritis and enteropathy.

Olmesartan is an angiotensin II receptor blocker (ARB) used for the management of hypertension. We report a case of Olmesartan-associated severe gastritis and enteropathy (OAE) in a 81-year-old female patient who presented with anorexia and weight loss. After discontinuation of the drug, her symptoms improved and follow-up gastroscopy showed endoscopic improvement. Histopathology showed a reduction of eosinophils and intraepithelial lymphocytosis, but a persisting increase in mast cells. Hence, systemic mastocytosis was excluded by further investigations. To our knowledge, this is the first case report of a patient with Olmesartan-associated severe gastritis with histopathological presence of mast cells. We conclude that mast cells, like eosinophils, could be druginduced, although systemic mastocytosis must be ruled out. Future studies should focus on the link between local mast cells and gastro-intestinal diseases.