Hereditary Angioedema and Gastrointestinal Complications

Hereditary angioedema is a chronic, genetic form of angioedema, a type of sudden, but temporary, swelling in the deeper layers of the skin. First appearing in childhood, it consists of large, smooth welts that can develop anywhere on the body.

Episodes of swelling are chronic or happen regularly over a long time, sometimes once or twice a week if untreated. Though the lips and the skin around the eyes are the most common sites, the tongue and the mucosal membranes of the throat, mouth, and intestines also may swell. These can be life-threatening and may require emergency medical care.

When severe swelling occurs in the intestines, the individual may experience nausea, vomiting, intense pain, or symptoms of shock. These can be mistaken for other diseases, including several that require surgery. But hereditary angioedema swellings do not need any intervention as the swellings and accompanying symptoms will dissipate on their own after three to four days.

In order to avoid putting the patient through unnecessary surgical procedures, which can itself trigger or worsen swelling attacks, it is important to identify when serious gastrointestinal problems and pain are caused by hereditary angioedema.

Gastrointestinal symptoms

Gastrointestinal swelling can happen in different types of angioedema, but is more common in hereditary angioedema. Gastrointestinal pain, which is intense and cramp-like, is present in 43-93 percent of cases.

Swellings usually show up on X-rays or other radiological imaging, but only as thickened walls or widened sections of the gut. Intussusception, where the wall of the intestine folds or “telescopes” in on itself, also may be visible through imaging.

Patients with gastrointestinal swelling usually experience nausea, loss of appetite, bouts of vomiting, and diarrhea. These usually are not bloody, though bloody diarrhea also can be present in rare cases. Constipation can occur if the swelling is located in the lower gut or the colon.

Hereditary angioedema swellings can be present in organs such as the liver and pancreas, blocking ducts and causing temporary episodes of liver problems and pancreatitis.

When at their most severe, gastrointestinal swellings or intussusceptions caused by hereditary angioedema may lead to shock, which can be life-threatening. This, alongside managing the intense pain, requires emergency medical care.

Hereditary angioedema versus other gastrointestinal diseases

The gastrointestinal symptoms seen in hereditary angioedema can resemble the symptoms of polyps, inflammation, tumors, or other abnormal growths. A detailed medical history and physical exam are necessary to diagnose the correct source of the gastrointestinal symptoms.

If a patient has a family history of hereditary angioedema, there is a good chance their symptoms may be caused by this condition rather than something else. Genetic testing can determine whether hereditary angioedema-induced gastrointestinal symptoms are a possibility.

Hereditary angioedema is inherited as an autosomal dominant trait and has a 50 percent chance to be passed from a parent with the condition to their children.

Blood tests for the C1-inhibitor (C1-INH) proteins, a protein that regulates inflammation, will show up as low if hereditary angioedema is present and will help confirm hereditary angioedema diagnosis.

Hereditary angioedema swellings will show up in radiography as thick or widened areas of the digestive tract, not as solid lumps as seen in tumors. Abdominal pain caused by hereditary angioedema also is nonspecific and does not become more intense when the abdomen is pressed, unlike appendicitis, for example.

The swellings often respond well to hereditary angioedema medications and treatments and will subside on their own within three to four days, unlike many gastrointestinal disorders.

Treating gastrointestinal symptoms of hereditary angioedema

Hereditary angioedema is treated with C1-inhibitor-boosting medicines such as Haegarda, Cinryze, and Kalbitor. Another medicine, Firazyr, can be used in much the same way as an EpiPen for immediate, self-treatment of a hereditary angioedema attack.

In many cases, these also will help resolve the gastrointestinal symptoms. But, in rare cases when they don’t, supportive care, such as intravenous fluids at a hospital, may be needed until the swelling goes down.


Angioedema News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.