The aim of acute treatment is to halt progression of the edema as quickly as possible, which can be life-saving, particularly if the swelling is in the larynx. In Germany, most acute treatment consists of C1 inhibitor concentrate from donor blood, which must be administered intravenously; however, in most European countries, C1 inhibitor concentrate is only available to patients who are participating in special programs. In emergency situations where C1 inhibitor concentrate is not available, fresh frozen plasma (FFP) can be used as an alternative, as it also contains C1 inhibitor.