Hereditary angioedema (HAE)

Also known as Quincke's disease - An Autosomal Dominant disease

Caused by a deficiency or dysfunction of the C1 esterase inhibitor, a protein of the complement system

People with hereditary angioedema can develop rapid swelling of the hands, feet, limbs, face, intestinal tract, larynx or trachea

Attacks of swelling can become more severe in late childhood and adolescence.

There is usually a family history of the condition. However, relatives may be unaware of previous cases, which may have been reported as an unexpected, sudden, and premature death

Investigations:

• C1 inhibitor function
• C1 inhibitor level
• Complement components C4 and C2
  Treatment:
  Antihistamines and other treatments used for angioedema are of limited benefit in hereditary angioedema. Epinephrine should be used in life-threatening reactions.

  The most effective treatment is a C1 inhibitor concentrate (not available in the US), but this may not be available. Fresh frozen plasma contains C1 inhibitor and will help an episode, but rarely, the swelling will become worse.

  Berinert P (CSL Behring), which is pasteurized C1 inhibitor, was approved by the F.D.A. in 2009 for acute attacks. Cinryze (ViroPharma), which is nanofiltered, was approved by the F.D.A. in 2008 for prophylaxis. Rhucin (Pharming) is a recombinant C1 inhibitor under development that does not carry the risk of infectious disease transmission due to human blood-borne pathogens.

  Newer treatments attack the contact cascade. Ecallantide (Kalbitor, Dyax) inhibits plasma kallikrein, and was approved by the F.D.A. (but not in Europe) for acute attacks in 2009. Icatibant (Firazyr, Jerini) inhibits the bradykinin B2 receptor, and was approved in Europe and approved by the FDA on August 25, 2011.

  
  

  Prophylaxis:

  Attenuated androgens, such as danazol, can reduce the frequency and severity of attacks by increasing the production of C1 inhibitor.

  Helicobacter pylori, a type of bacteria found in the stomach, can trigger abdominal attacks. Getting rid of the bacteria with antibiotic therapy decreases these abdominal attacks.
  Hereditary angioedema can be life threatening and treatment options are limited.

  Courtesy: www.ncbi.nlm.nih.gov, youtube - HAE.org website and Wikipedia