[A Case Report of Acute Angioedema that Showed Dramatic Response to Administration of a C1-inactivator].

Angioedema is characterized by rapid and severe swelling of the subcutaneous and submucosal tissues. Angioedema involving the upper airway can lead to life-threatening airway obstruction, and needs prompt diagnosis and treatment. Herein, we report a case of acute angioedema which was suspected as having been caused by estrogen imbalance. A 32-year-old woman who was taking a fertility drug for infertility treatment, presented with sudden swelling of the face and neck region and breathing difficulty. Her symptoms continued to progress despite antibiotic and corticosteroid administration. We suspected hereditary angioedema (HAE), and administered a C1-inactivator, which led to immediate and dramatic resolution of the symptoms. Since the C4 and C1-inhibitor levels were normal, the possibility of HAE type III was considered. However, another possibility was that her complicated hormonal condition, including oral intake of a fertility drug, menstruation, and mental stress may have led to estrogen imbalance causing angioedema. Currently, a variety of hormone therapies is widely used ; therefore, caution is needed against the development of estrogen-dependent angioedema.