Patients with angioedema can present to the internal medicine, emergency medicine, dermatology, or ear nose throat clinics. Physicians may need to assess the patients whose angioedema is unresponsive to antihistamines systematically in collaboration with other subspecialties including hematology, rheumatology, allergy, and immunology. We aimed to provide a concise review of the diagnosis and multi-disciplinary management of acquired angioedema through a case presentation.A 61-year-old woman presented with recurrent angioedema of 4 episodes within one year. She was evaluated by various disciplines such as dermatology and emergency medicine. Antihistamines and steroids were not effective. The complete blood count (CBC) results indicated lymphocytosis (lymphocyte count=9100 k/μL) and further evaluation of the lymphocytosis with flow cytometry immunophenotyping confirmed a diagnosis of chronic lymphocytic leukemia. Since the acquired angioedema diagnosis was confirmed with low C4, C1q, and C1 esterase inhibitor levels, Rituximab 375 mg/m2 was administered once a week for 4 weeks. The frequency of attacks decreased after rituximab therapy and none of them were life-threatening.In conclusion, when the effective treatment is initiated for the primary diagnosis in acquired angioedema, the numerous emergency department visits, hospitalizations, and the mortality due to life-threatening angioedema episodes can be avoided.