Hereditary Angioneurotic Edema

Etiology
D/t deficiency of C1 esterase inhibitor

Pathogenesis
Increased production of bradykinin and c2 kinins due to enhanced activity of activated C1 and enhanced expression of activated kallikrein and factor 12

Laboratory features
. ↓C1 esterase inhibitor (Type 1)
. Dysfunctional/non functional C1 esterase inhibitors (Type2)
. Normal C1 levels with reduced C4 and C2 levels
. ↑ levels of bradykinin and C2 kinins

Clinical features
. Positive family history
. Recurrent episode of edema ( characteristic provoked by emotional stress or trauma)
. Laryngeal edema
. Edema affects intestinal mucosa (colic)
. Affects skin and extremities