As compared to histaminergic angioedema, nonhistaminergic angioedema was associated with angiotensin-converting enzyme inhibitors (ACEI) or use of angiotensin II receptor blockers (ARB) (odds ratio [OR] [60.9]; 95% confidence interval [CI], 23.16–160.14) and time of onset one hour or more prior to ED arrival (OR [5.91]; 95% CI,1.87–18.70) and was inversely associated with urticaria (OR [0.05]; 95% CI, 0.02–0.15), dyspnea (OR [0.23]; 95% CI, 0.08–0.67), and periorbital or lip edema (OR [0.25]; 95% CI, 0.08–0.79 and OR [0.32]; 95% CI, 0.13–0.79, respectively). The gene discussed is ACE; the disease is urticaria.