Hereditary Angioneurotic Oedema (HAE)
Angioedema is a well-demarcated, localized oedema of the skin and suncutaeeous tissues (urticaria oedema involves dermis alone). There si local venodilation and perivenular infiltrates of lymphocytes, eosinophils, and neutrophils.
Introduction
- Type 1 - 85% deficiency of C1E - INH
- Type 2 - 15% enzyme normal C1E - INH dysfunctional
- C1E-INH is a serine protease inhibitor. It is the major inhibitor of both factors 12A and kallikrein and the only known inhibitor of activation of C1 from complement pathway
- C1E-INH regulates the activity of two plasma cascade systems. Responsible for vasodilation and vasopermeability
- HAE patients have reduced or abnormal C1E-INH causing uncontrolled activation of complement and coagulation cascade, particularly in increasing bradykinin resulting in angio-oedema
- Acute attacks are precipitated by trauma (dental), anxiety and stress
- Occasionally triggered by glomerulonephritis, rheumatoid arthritis, thyroiditis, Sjogren's syndrome, and pernicious anaemia
- ACE inhibitors can also cause particularly in healthy people.
Clinical findings
HAE presents as
- Acute abdominal pain
- Ascites and recurrent abdominal pain
- Facial and upper airway obstruction
Long term treatment
- FFP also useful as prophylaxis of HAE
- Long-term prophylaxis for HAE is Danazol and Stanozolol
- (androgen therapy to increase synthesis of CN1-INH)
- Epsilon aminocaproic acid and tranexamic acid also used
- Remember to check detailed family history
Treatment
Immediate management
- Airway management
- (surgical airway early if necessary)
- IV fluids
- Analgesia
- SDP
- C1-INH concentrate (usually on an individual named basis only)
