What You Need to Know About This Mysterious Swelling Disease

Hereditary angioedema is a rare disease that often goes undiagnosed for years

swollen foot

If you tuned in to our recent episode, you met Monique and Torri – two sisters who each endured a lifetime of pain that was previously undiagnosed. It turns out they’ve been living with a condition called hereditary angioedema.This condition is quite rare and is estimated to only affect between one in 10,000 to 1 in 50,0000 people. Let's have a look inside hereditary angioedema; the three types of the condition; and what's involved with diagnosing and then managing the disease.

What is hereditary angioedema?

Hereditary angioedema (HAE) is a potentially life-threatening genetic condition. If you have the condition, you are born with it rather than acquiring it or developing the disease later in life.
While humans have between 20,000-25,000 genes in our bodies, hereditary angioedema is typically caused by a “glitch” in one particular gene. The affected gene is responsible for controlling a blood protein called C1 inhibitor. This gene defect causes a chemical imbalance in the body that causes swelling. If you think of genes as our body's "how-to" manuals, a mutated gene can wreak havoc when it doesn't send the right instructions.
Most people with the disease have their first attack in childhood. Puberty tends to increase the attacks. Episodes tend to affect three major parts of the body:

  • Skin: Swelling most commonly occurs on the face, legs, arms, hands, buttocks and genitals. The swelling typically comes with pain, disfigurement, or dysfunction, but it is generally temporary and not dangerous.
  • Gastrointestinal tract: The swelling can cause abdominal pain, nausea, vomiting and diarrhea.
  • Airway: This is the most dangerous area of swelling and can cause, in rare cases, complete airway obstruction.

Is there more than one type of HAE?

There are three types of HAE.
The first two types of HAE involve the "glitch" described above, caused by a mutation in the C1NH gene (or SERPING1 gene). Type 1 is a deficiency in c1 inhibitor, and Type 2 is a dysfunction in the c1 inhibitor created by the body. These two types typically have their first appearance in childhood or adolescence.
The third type of HAE typically doesn’t present until adulthood. Those with Type 3 HAE usually have normal C1 inhibitor and complementary protein levels. However, it’s thought that this type of HAE could be caused by a mutation of the F12 gene.
The symptoms are similar for all three types of HAE.

How is this condition diagnosed?

For the most commonly diagnosed form of HAE, if you have a parent with HAE, you have a 50 percent chance of developing HAE as well. However, 25 percent of people diagnosed with HAE don’t have a family history of the disease.
Flare-ups of HAE commonly occur every one to two weeks with episodes lasting between three and four days each. The episodes can be incredibly painful, limit activity and even cause difficulty breathing. If multiple people in the same family have HAE, they all may have different severity of symptoms.
As HAE often goes undiagnosed for years due to its rarity, a good first step is to find out if you have a parent with similar symptoms or previous HAE diagnosis. As HAE often goes undiagnosed for years due to its rarity, you may have a parent with HAE who's unaware of their condition.
The next steps to diagnosing HAE are blood tests that test for the C1 inhibitor and complement proteins in the blood.
Those living with HAE often find that various life events trigger HAE episodes. Common triggers include, but aren’t limited to:

  • Minor illness, like the cold or flu
  • Menstrual periods
  • Birth control containing estrogen
  • Stress or anxiety
  • Medications, most commonly those used for congestive heart failure or high blood pressure


Monique and torri were diagnosed with hae in episode two of chasing the cure 

What treatments are available?

It’s important to know that medications typically taken for acute swelling or histamine reactions like antihistamines and corticosteroids aren’t effective in treating HAE.

For adults, there is a wide variety of medications approved to treat HAE.

For children diagnosed with HAE, treatments are a bit more complicated. Physicians typically work with children and their families to tailor a treatment plan to guide them through to adulthood.

While rare, HAE is a disease with hope. Once someone is aware that their pain and swelling is being caused by a genetic disorder, they can work with their physician to find reasonable solutions to manage symptoms. This can lead to fewer worries about episodes and overall higher quality of life.

E. Napoletano is an award-winning journalist and the recipient of the 2019 Illinois Women’s Press Association first-place prize for her feature on the traumatic effects of family separation policies at the border.