Angioedema related to angiotensin-converting enzyme inhibitors

Angioedema is a disorder characterized by well-demarcated nonpitting edema involving the tongue, floor of the mouth, larynx, lips, and face. This condition can progress to upper airway obstruction and death. Angiotensin-converting enzyme inhibitors (ACEIs), relatively new antihypertensive agents, act by blocking the formation of angiotensin II, a potent vasoconstrictor and stimulator of aldosterone formation. ACEIs also retard the breakdown of bradykinin, a potent vasodilator, which may lead to the edema seen in nonhereditary angioedema. These ACEIs include enalapril, captopril, lisinopril, saralasin acetate, and a combination of ACEI with diuretics (for example, Capozide). From August 1987 to January 1989, we treated six patients with a nonhereditary form of angioedema related to ingestion of angiotensin-converting enzyme inhibitors. Symptoms developed in all patients within 12 hours after their initial dose of an ACEI. They presented with shortness of breath and dysphagia associated with tongue and floor of the mouth edema. Two of the six required intubation and monitoring in the surgical intensive care unit for 36 to 48 hours. Three required supportive treatment and observation in an intermediate care unit, and one received supportive care in the clinic and was discharged the same day. Specifically, treatment consisted of cessation of inciting agent, steroids, antihistamines, and epinephrine, if not otherwise contraindicated. Assays of C1 esterase inhibitor levels and C4 were normal in all six patients; this was important in order to rule out hereditary forms of angioedema. These cases will be discussed, including a review of the literature, methods of diagnosis, pathophysiology, and treatment of angioedema.