Idiopathic angioedema and urticarial vasculitis in a patient with a history of acquired haemophilia

Abstract

Angioedema is a potentially life-threatening disease categorised into several forms such as allergic, hereditary, acquired autoimmune and idiopathic. Allergic angioedema is dependent on histamine release, whereas mutations in the C1-inhibitor and factor XII genes have been described in hereditary angioedema (1, 2). Bradykinin-induced acquired angioedema is often caused by antibodies to C1-inhibitor, increased consumption of C1-inhibitor in cases of malignancies or autoimmune diseases (2, 3). Angioedema may also be idiopathic (4). Bradykinin, released during activation of the kallikrein-kinin system, is the main mediator of oedema in hereditary angioedema. It is assumed that the kallikrein-kinin system, linked to the coagulation system via factor XI and factor XII, is also activated in cases of idiopathic angioedema (5, 6). Here, we report an unusual case of therapy resistant idiopathic angioedema, normocomplementaemic urticarial vasculitis and a history of autoimmune acquired haemophilia. Emerging evidence suggests that coagulation and inflammatory responses are interlinked (7–9), as illustrated by this case.