Table 2.

Classification of angioedema.

Bradykinin-induced AE				Mast cell mediator-induced AE		Unknown mediator
C1–INH deficiency/defect		C1–INH normal		IgE mediated	non-IgE mediated
Inherited	Acquired	Inherited	Acquired
HAE-1 HAE-2	AAE-C1-INH	HAE-nC1-INH (HAE-FXII, HAE-PLG, HAE-KNG1, HAE- HS3ST6, HAE-ANGPTI+, HAE-MYOF+, HAE-UNK)	ACEI-AE Other drug-induced AE∗	Angioedema with Anaphylaxis Angioedema with or without wheals (Urticaria)	Angioedema with or without wheals (Urticaria)	Idiopathic AE

HAE-1: Hereditary angioedema due to C1-Inhibitor deficiency; HAE-2: Hereditary angioedema due to C1-Inhibitor dysfunction; AAE-C1-INH: acquired angioedema due to C1-Inhibitor deficiency; HAE-nC1-INH: Hereditary angioedema with normal C1-Inhibitor levels, either due to a mutation in FXII (Factor 12), ANGPT1 (angiopoietin-1), PLG (plasminogen), KNG1 (kininogen), MYOF (myoferlin), and HS3ST6 (heparan sulfate-glucosamine 3-O-sulfotransferase 6) or unknown (UNK). ⁺ HAE-ANGPT1 and HAE-MYOF are due to mutations involving the vascular endothelium and the role of bradykinin as mediator of angioedema symptoms seems to be an indirect or conditional one. ACEI-AE angiotensin converting enzyme inhibitor-induced angioedema, ∗ other drugs like Angiotensin II receptor blockers, gliptins, neprilysin inhibitors or tissue plasminogen activators are thought to potentially induce bradykinin-mediated AE