Angioedema: Difference between hereditary and acquired

Hereditary and acquired angioedema are triggered by a deficiency or malfunction of C1 inhibitor which is a component of the immune system. Both conditions cause repeated episodes of swelling beneath the skin.

Both types are strikingly similar to angioedema caused by an allergic reaction with swelling of a region of tissues beneath the skin. Nevertheless, hives do not manifest and the cause is different.

Hereditary angioedema

This is a genetic condition that results to a deficiency or malfunction of the C1 inhibitor. Take note that the C1 inhibitor is one of the proteins in the complement system which is part of the immune system. The symptoms usually start during childhood or adolescence.

Acquired angioedema

Angioedema

The lips, face, hands, tongue, feet, genitals and other parts of the body might swell as well as the membranes lining the mouth, airways, throat and digestive tract.

This is a rare condition that develops if certain cancers or autoimmune disorders cause a deficiency of the C1 inhibitor. The symptoms typically start later in life after the individual develop the condition that caused the deficiency.

In both the acquired and hereditary type, the swelling can be triggered by the following:

  • Viral infection
  • Minor injuries
  • Certain foods
  • Exposure to cold
  • Pregnancy

Being stressed out such as having a dental or surgical procedure can aggravate the angioedema.

What are the symptoms?

The lips, face, hands, tongue, feet, genitals and other parts of the body might swell as well as the membranes lining the mouth, airways, throat and digestive tract. In most instances, the affected area is minimally painful but not itchy.

Remember that hives do not manifest. It is common for abdominal pain, nausea and vomiting to occur. In some cases, swelling of the larynx, tongue or throat can disrupt normal breathing.

How is it diagnosed

The doctor will suspect acquired or hereditary angioedema if both are present:

  • There is swelling in the lips, face, hands, feet, tongue, genitals and/or other parts of the body without hives.
  • The swelling recurs and the exact cause is not evident.

In case the family members also have symptoms, the doctor will suspect hereditary angioedema. Additionally, diagnosing also requires measuring the C1 inhibitor levels or activity in a blood sample.

Treatment

There are certain drugs that can alleviate the swelling such as ecallantide or purified C1 inhibitor. Nevertheless, these medications are not always on hand. In such instances, fresh frozen plasma might be given. Pain medications and antiemetic drugs along with fluids can also help alleviate the symptoms.

Emergency care

Oftentimes, if the airways abruptly swell and there is difficulty breathing, the doctor should open the airway. This is done by injecting epinephrine beneath the skin or into the muscle to minimize the swelling. Nevertheless, epinephrine might not minimize the swelling rapidly enough or long enough. In such cases, the doctor has to insert a breathing tube in the windpipe via the nose or mouth.

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