What is HAE?

Understanding HAE

What is Hereditary Angioedema (HAE)?

Hereditary angioedema (HAE) is a rare blood disorder resulting from a deficiency in C1 esterase inhibitor. It is a chronic, potentially life-threatening illness that causes episodes of swelling commonly affecting the face, throat, abdomen, and extremities.  If left untreated, an upper airway obstruction can prove fatal for hereditary angioedema patients.

HAE is a rare disorder and affects only a few hundred Canadians, approximately one in every 10,000-50,000 people. Because it is so rare, many physicians are not familiar with the disease and, for many patients, getting a diagnosis can be a long and frustrating process.

Recognizing hereditary angioedema is also difficult because it manifests differently in each patient. Like Multiple Sclerosis, the course of the disease is unpredictable and often changes over the lifetime of each patient.

The majority of people with hereditary angioedema have a defective gene that results in their body producing inadequate or non-functioning C1 Inhibitor – the blood protein that stops swelling. As a result, hereditary angioedema patients experience episodes of swelling that commonly affect the throat, abdomen, face and extremities. Patients often have bouts of extreme abdominal pain, nausea, vomiting and diarrhea caused by swelling in the intestinal wall. Anyone who experiences even the slightest hint of throat swelling should seek immediate medical attention. If left untreated, an upper airway obstruction can prove fatal for hereditary angioedema patients.

Hereditary angioedema symptoms tend to mimic other conditions such as allergies, appendicitis and ovarian cysts. When hereditary angioedema is misdiagnosed as an allergy it is most commonly treated with steroids and epinephrine, drugs that are usually ineffective in treating a hereditary angioedema episode. Other misdiagnoses have resulted in unnecessary exploratory surgery for patients with abdominal swelling and other hereditary angioedema patients report that their abdominal pain was wrongly diagnosed as psychosomatic. Many hereditary angioedema patients have been accused of drug-seeking.

An accurate and timely diagnosis is often life changing for people suffering from hereditary angioedema. Canadian patients are fortunate to have access to treatment that can dramatically improve the quality of life for even the mildest cases of hereditary angioedema. For more information please refer to the Frequently Asked Questions.

View an online educational module about HAE.