was significantly longer in patients with urticaria (p<0.001), but the presence of urticaria did not predict admission. A probable cause was identified in 48.8% of visits. Periorbital angioedema was associated with environmental, contact, and insect sting allergy (p<0.001). 58.3% of patients with angioedema due to drug allergy had lip angioedema (p=0.032). C1 esterase inhibitor deficiency was most frequently associated with a history of previous episodes. Several factors were found to predict admission, including NSAID-induced angioedema (OR=15.3), epinephrine treatment (OR=8.34), hypotension (OR=15.7), multiple site angioedema (OR=4.25), pharyngeal angioedema (OR=1.23), and tongue angioedema (OR=4.62). Conclusions This large cohort retrospective review confirms causeclinical associations in angioedema and demonstrates novel predictors of morbidity, with implications in clinical practice.