Recurrent Angio‐Oedema without Weals

Abstract Angio‐oedema without weals may be hereditary or acquired. Nearly all types and cases of hereditary angio‐oedema (HAE) are mediated by bradykinin and require completely different assessment and treatment to acquired mast cell mediator‐induced angio‐oedema. It is inherited as an autosomal dominant disorder. Types 1 and 2 are due to mutations in SERPING1 resulting in deficient or non‐functional C1 esterase inhibitor (CI‐INH) respectively. Hereditary angio‐oedema with normal C1‐INH is associated with several different mutations including gain‐of‐function mutations in F12 . Bradykinin also causes angio‐oedema linked to treatment with angiotensin converting enzyme inhibitors or acquired C1‐INH deficiency resulting from its consumption or its inactivation by autoantibodies. About 10% of patients with chronic spontaneous urticaria present with mast cell mediator‐induced angio‐oedema without weals, thus it is much commoner than HAE. The assessment and treatment are similar to that in urticaria patients with weals. Acquired idiopathic angio‐oedema does not appear to be bradykinin or mast cell mediator induced. The entity is poorly defined as there are no diagnostic tests.