OBJECTIVES: We aimed to compare and distinguish the characteristics of anaphylaxis and angioedema, especially with oral mucosal involvement and treatment of patients who visited the Pediatric Emergency Department. METHODS: We retrospectively analyzed patients under age 18-year-old who were diagnosed with anaphylaxis and angioedema with oral mucosal involvement and treated with epinephrine from May 2008 to May 2013 in a single Pediatric Emergency Department in Seoul, Korea. We evaluated their past history, possible triggering causes, symptoms, vital signs and treatment and discharge with education. RESULTS: During the study period the total cases of anaphylaxis were 79 and angioedema with oral mucosal involvement were 218. The age of patients with anaphylaxis was significantly higher (6.6+/-4.9 years vs. 4.1+/-3.3 years). The heart rate relative to age was significantly higher in the anaphylaxis group (49.4% vs. 36.2%). After discharge from the Emergency Center, 3.8% of anaphylaxis patients were prescribed an epinephrine injection. Education to avoid the triggering factor was provided in 32.9% of anaphylaxis group and 17.4% in the angioedema group. CONCLUSION: Besides blood pressure, we should pay attention to the heart rate in pediatric patients with severe allergic reactions. More active follow-up of anaphylaxis and angioedema with oral mucosal involvement is needed to educate parents and prescribe emergency medication.