Hereditary angioedema (HAE)

What is Hereditary Angioedema?

Hereditary angioedema (HAE) is a genetic condition that is potentially life-threatening. It is characterised by sudden swelling of different parts of the body (mainly face and airway tract) and accompanied by excruciating abdominal pain, nausea, and vomiting. It essentially affects the immune system.

What are its signs and symptoms?

The signs and symptoms of HAE include

• Non-itchy red rash
• Throat swelling, causing blockage of the airway and sudden hoarseness
• Abdominal cramping episodes that are recurrent without any obvious cause
• Swelling of the eyes, tongue, lips, throat, larynx (voice box), trachea (windpipe), intestines, arms, hands, legs, or genitals
• Occasional severe swelling of intestines can be seen. It causes pain, abdominal cramping, diarrhoea, vomiting, dehydration, and rarely shock

What are its main causes?

This condition can be caused by either insufficient levels or improper function of a protein called C1 inhibitor, which eventually affects the blood vessels causing swelling.

How is it diagnosed and treated?

The diagnosis of HAE is mainly considered by the physician based on signs and symptoms and after a physical examination and the following tests, which are ideally done during an episode:

• Complement component 4
• C1 inhibitor function
• C1 inhibitor level

The treatment of HAE is mentioned below:

• The type of medication used to treat the condition depends on various factors, such as the age of the patient and the location of the symptoms. These medications can be either given orally, self-administered by the patient by injecting under the skin or intravenously (IV)
• Some medications are
  • Cinryze
  • Berinert
  • Ruconest
  • Kalbitor
  • Firazyr

• Traditionally androgen medicines, such as danazol, were used, which help in reducing the frequency and intensity of attacks
• Treatment is given to relieve pain
• Fluids are given through IV
• As abdominal attacks are triggered by Helicobacter pylori (gut bacteria), individuals are treated with antibiotics to reduce the abdominal attacks
• In cases of life-threatening reactions, epinephrine should be administered

1. MedlinePlus Medical Encyclopedia: US National Library of Medicine; Hereditary angioedema
2. National Institutes of Health. Hereditary angioedema. U.S Department of Health and Human Services; [Internet]
3. National Centre for Advancing Translational Science. Hereditary angioedema. U.S Department of Health and Human Services.
4. National Organization for Rare Disorders. Hereditary Angioedema. [Internet]
5. Abdulkarim A, Craig TJ. Hereditary Angioedema. Hereditary Angioedema. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-.