Hereditary Angioedema

Key points

• Hereditary angioedema is an autosomal dominant condition associated with low plasma levels of the C1 inhibitor (C1-INH) protein.
• C1-INH level is low during an attack
• low C2 and C4 levels are seen, even between attacks. Serum C4 is the most reliable and widely used screening tool Symptoms
• attacks may be proceeded by painful macular rash
• painless, non-pruritic swelling of subcutaneous/submucosal tissues