Table 2.

Laboratory diagnosis of angioedema.

Type of Angioedema	C1-INH level	C1-INH function	C4	C3	C1q
Type I HAE	Low	Low	Low	Normal	Normal
Type II HAE	Normal	Low	Low	Normal	Normal
Type III HAE	Normal	Normal	Normal	Normal	Normal
AAE	Low	Low	Low	Normal/Low	Low
ACE inhibitor	Normal	Normal	Normal	Normal	Normal
Idiopathic	Normal	Normal	Normal	Normal	Normal

C1-INH: C1 inhibitor, HAE: hereditary angioedema, AAE: acquired angioedema, ACE: angiotensin-converting enzyme.