A Rare Case of Losartan-Induced Visceral Angioedema.

The following describes a case of isolated visceral angioedema related to an angiotensin II receptor blocker (ARB) medication. Additionally, we discuss the pathophysiology of drug-induced angioedema, various presentations that can be encountered, and the leading theorized mechanisms of how renin-angiotensin-aldosterone system (RAAS) blocking medications lead to angioedema. The goal of sharing this case is to help increase awareness of the possibility of ARB-induced angioedema and to recommend keeping visceral angioedema as part of the differential diagnosis when presented with a patient who is taking an angiotensin converting enzyme inhibitor (ACEI) or ARB medication that is experiencing gastrointestinal symptoms of unclear etiology.