Lupus-associated Angioedema Successfully Treated with C1 Esterase Inhibitor Concentrate in an Adolescent Female: A Case Report

Introduction: Acquired angioedema is a rare complication of systemic lupus erythematosus (SLE). This type of angioedema is bradykinin-mediated and thought to be due to an acquired antibody against C1 esterase inhibitor (C1-INH). It can be difficult to manage and is often refractory to standard therapies. This case aims to describe the presentation of refractory angioedema as a presenting feature of SLE in a patient and her clinical course. She was treated with intravenous C1-INH and had a dramatic clinical improvement. The use of intravenous C1-INH in lupus-associated angioedema has not been previously reported in the literature, but could be a life-saving treatment option for those with this rare presentation. Abstract: Our case features a 17-year-old African American female with a remote past medical history of neuromyelitis optica. The patient was in her usual state of health until 6 months prior to the admission, when she developed polyarthritis and was treated with low-dose prednisone intermittently by her primary care physician. The patient presented to the emergency room with acute chest pain and respiratory distress. Her initial laboratory workup was significant for pancytopenia and systemic inflammation. Chest radiograph revealed a left pleural effusion. A transthoracic echocardiogram demonstrated a small pericardial effusion. She had a chest tube placed and fluid study suggested exudative pleural effusion. Patient was admitted for further management. On the first night of admission, she developed progressive angioedema of the airway which was refractory to epinephrine and required emergent intubation in the operating room by ENT. She was transferred to PICU and was started on methylprednisolone, IVIG and was given a dose of intravenous C1-INH concentrate. Her angioedema improved significantly within 30 minutes after the medication was given. She was able to be extubated the following day and was transferred back to the general pediatric floor. Her laboratory studies came back consistent with the diagnosis of SLE. She was able to be discharged home on day 5 of her hospital stay. She had two subsequent minor angioedema flares on day 12 and 14 which also responded clinically to intravenous C1-INH concentrate. Discussion: In our case, other causes of angioedema such as allergic reactions were excluded on the basis of history and lack of response to epinephrine. Hereditary angioedema was also thought to be unlikely considering the age of presentation and in the absence of family history. Our patient was treated with C1-INH concentrate and she showed a dramatic clinical response. She had two subsequent minor angioedema flares which also responded well clinically to intravenous C1-INH concentrate. The use of intravenous C1-INH concentrate in lupus-associated angioedema has not been previously reported in the literature, but could be a life-saving treatment option for patients with this rare presentation.