Allergic and idiopathic angioedema
Allergic angioedema and idiopathic angioedema are usually treated in a similar way.
Avoiding particular substances or activities that trigger your symptoms may help reduce your chances of experiencing swelling.
For example, if you're allergic to a certain type of food, it can help to check the ingredients in food you buy and be careful when eating out.
Read about preventing allergic reactions for more advice.
Antihistamines and steroid medicine
Your GP may suggest taking antihistamines to reduce swelling when it occurs.
Antihistamines work by blocking the effects of histamine, one of the chemicals responsible for the swelling. Some types can be bought in pharmacies and supermarkets without a prescription.
Some antihistamines can make you feel drowsy. Avoid driving, drinking alcohol or operating dangerous machinery if you experience this. If your symptoms of swelling occur during the day, it's best to take non-drowsy medicines such as cetirizine and loratadine.
Other side effects of antihistamines can include:
If the swelling is severe, your GP may prescribe a short course of steroid medicine. This is a powerful medicine that's only used for short periods because it can have troublesome side effects.
If you have a particularly serious allergy, you may be given adrenaline auto-injectors to use if you experience a severe allergic reaction (anaphylaxis).
There are several types of auto-injector, which are used in slightly different ways.
Read about preventing anaphylaxis for more information.
If a certain medicine you're taking is thought to be responsible for your angioedema, your doctor 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 doctor if your symptoms continue or come back after switching medicine.
Hereditary angioedema cannot be cured, but medicines can help prevent and treat the swelling.
Medicines called danazol and oxandrolone can help reduce the chances of swelling occurring if you have hereditary angioedema.
These medicines boost the levels of C1 esterase inhibitor in your blood. Low levels of this substance are what causes the swelling.
Side effects of these medicines can include:
- weight gain
- in women, excessive body or facial hair growth, deepening of the voice, irregular periods or absent periods
- high blood pressure
- liver problems
A medicine called tranexamic acid may sometimes be used as an alternative, particularly in children and women. This causes fewer side effects, but may not be as effective in preventing swelling.
The 2 main treatments used to treat swelling caused by hereditary angioedema are:
- icatibant – a medicine given by injection that blocks the effects of some of the chemicals responsible for the swelling
- C1 esterase inhibitor replacement – a treatment given by injection that boosts the levels of C1 esterase inhibitor in your blood
Occasionally, C1 esterase inhibitor replacement may also be used shortly before surgery or dental treatment, as it can reduce the risk of these triggering swelling.
You may be given a supply of medicine to keep at home and be taught how to give the injections yourself.