Angioedema

Angioedema involves swelling in the deep layers of your skin. The most common areas affected are your face, lips, tongue, throat and genitals. Swelling in one area usually lasts between 1 to 3 days. Occasionally, swelling of internal organs, eg, your oesophagus (food pipe or gullet that leads to the stomach), stomach, or bowel can trigger chest or stomach pains.

The release of chemical called histamine from some of the immune cells within your skin seems to be the trigger for swelling in most people. The most common triggers for this are allergy,  ACE inhibitor medicines, hereditary angioedema (HAE), acquired C1-inhibitor deficiency and infection.

Allergies

Angioedema is often the result of an allergic reaction. This is where your body mistakes a harmless substance, such as a certain food, for something dangerous. It releases chemicals (eg, histamine) into your body to attack the substance, which causes swelling.

Angioedema can be triggered by an allergic reaction to:

• food – particularly nuts, shellfish, milk and eggs
• medicine – including some antibiotics, aspirin and non-steroidal anti-inflammatory drugs (NSAIDs), eg, ibuprofen
• insect bites and stings – particularly wasp and bee stings
• latex – a type of rubber used to make medical gloves, balloons and condoms.

Angioedema caused by allergies is known as allergic angioedema. Allergic disease is almost never the cause of swelling that lasts for days or comes back over and over for weeks at a time.

Medicines

Some medicines can cause angioedema – even if you're not allergic to the medicine. Most swellings appear within the first few months of starting the medicine but sometimes you may not have any reaction for months to years, or it may only happen when your dose is increased.

Medicines that can cause angioedema include:

• angiotensin-converting enzyme (ACE) inhibitors, eg cilazapril, enalapril, lisinopril, perindopril and ramipril, which are used to treat high blood pressure and heart problems, ibuprofen and other types of non-steroidal anti-inflammatory painkillers
• angiotensin-2 receptor blockers (ARBs), eg, candesartan, irbesartan, losartan, olmesartan and valsartan – another medicine used to treat high blood pressure.

Angioedema caused by medicine is known as drug-induced angioedema.

The swellings from these medications are not itchy or painful, usually occur around your face, tongue and throat and are not accompanied by hives. It can take a few weeks after stopping the medicine for the swelling to go down. 

Hereditary angioedema (HAE)

Rarely, angioedema occurs because of a genetic defect. These people have low levels (deficiency) or reduced effectiveness of C1-inhibitor enzyme – a chemical which slows down certain immune reactions. How often the swelling occurs can vary. Some people experience it every week, while others experience it less than once a year.  If you have HAE, you have a 50/50 chance of passing it on to your children. Read more about hereditary angioedema (HAE).  

Acquired C1-inhibitor deficiency

In even rarer cases, low levels of C1-inhibitor occur in association with some cases of lymphoma, malignancies or autoimmune diseases, eg, systemic lupus erythematosus (SLE). 

Infection

A viral infection is the most common cause of hives and angioedema in children, especially if they last for more than 24 hours. 

Other causes

Thyroid gland disease and some types of inflammatory arthritis are more common in people with hives and angioedema. In some people whose swellings continue for years without an obvious cause, an autoimmune process may be responsible. This means that part of your body's immune system may be attacking your skin. 

In most cases, a single cause isn't found. 

Swelling

The main symptom is swelling. It may be itchy, tingling or burning, but often there are no symptoms other than the discomfort of the swelling. Swelling caused by angioedema can develop suddenly or come on gradually over a few hours. It normally lasts a few days.

The most common areas of your body affected are your face, lips, tongue, throat and genitals. Sometimes the swelling can be painful, particularly when it occurs over your joints. These swellings can be large and may last for days.

Swelling in one area usually lasts between 1 to 3 days. Occasionally, swelling of internal organs, eg, your oesophagus, (food pipe or gullet that leads to the stomach), stomach or bowel can trigger chest or stomach pains.

If swelling is constant rather than coming and going, other possible causes of swelling should be considered.

Rash

Often, the swelling occurs with a raised, itchy rash called urticaria (hives). The rash will usually settle in a few days. Otherwise, the skin over the swelling may feel tight and painful but look normal.

Other symptoms

Less common symptoms of angioedema include:

• difficulty breathing
• red, irritated eyes (conjunctivitis)
• tummy (abdominal) pain
• nausea (feeling sick) 
• diarrhoea (runny poo)
• dizziness
• fainting. 

The only danger from angioedema is if your throat or tongue swell severely, as this can cause difficulty breathing. Severe throat swelling requires early use of medicine (eg, adrenaline for anaphylaxis) and transfer to hospital by ambulance.

Swelling on the outside of your neck is uncomfortable but doesn't affect your breathing. Swelling that interferes with breathing is uncommon, even in people with recurrent angioedema.

If you have recurrent (coming and going) angioedema you should be referred by your healthcare provider to a clinical immunology/allergy specialist to see if there's an underlying cause and to optimise treatment.

The treatment for angioedema depends on what's causing it

There are several different types of angioedema, each of which has a different cause. Angioedema can usually be treated at home, but if you have a severe case you may need to be treated in hospital.

Your symptoms may disappear over time without any treatment. Some people only have a single episode, whereas others suffer from repeated bouts, which eventually stop for no apparent reason.

Change medicines

If a certain medicine is thought to be causing your angioedema, your healthcare provider will usually advise stopping it. They can prescribe a different medicine for you to take instead. This is usually all that needs to be done. Tell your healthcare provider if your symptoms continue or come back after switching medicines.

Avoid aggravating factors

Avoiding excessive heat, spicy foods and alcohol as these things can make angioedema worse. Aspirin should be avoided unless you're already taking it without a problem.

Take antihistamines

Antihistamines block the effect of histamine which is usually the cause of the swelling. Since they take 1 to 2 hours to reduce symptoms, it's often better to take them regularly, rather than as needed. The aim is to stop the episodes of swelling or to make them less frequent or less severe.

If you have severe angioedema, it's often better to take antihistamines every day, stopping every month or two to see if they are needed, and restarting them if they are.

Different people respond best to different antihistamines. Non-sedating antihistamines (eg, cetirizine, fexofenadine and loratadine) are less effective for angioedema than for hives and are often don't work at all for the non-itchy angioedema.

Other medicines

Other medicines are usually reserved for when angioedema can't be prevented by taking antihistamines. They are generally given under specialist supervision because they're more likely to have side effects.

Angioedema eventually disappears for most people. It may reappear following an infection when you're under stress or for no particular reason that can be identified. Occasionally it's a problem that comes and goes throughout life.