Most cases of urticaria don't need treatment, because the symptoms are usually mild and often get better within a few days.
Short-term (acute) urticaria
If your symptoms are troublesome or persistent, antihistamines are available over the counter from pharmacies.
See your GP or speak to your pharmacist if your symptoms get worse. If your symptoms are very severe, your GP may prescribe other medications, such as a short course of corticosteroid tablets.
Go back to your GP if your symptoms get worse or if the treatment hasn't worked after two weeks.
Antihistamines block the effects of histamine, helping to stop the itchiness and reduce the rash. Examples of antihistamines include:
For most people, modern antihistamines don't cause drowsiness, although there are some exceptions. See how you react to the antihistamine before driving or operating heavy machinery. Antihistamines may also cause drowsiness if taken with alcohol. Always read the information leaflet that comes with the medication.
Antihistamines aren't usually prescribed to pregnant women, as it's not known whether they're entirely safe. However, chlorphenamine may be recommended if it's believed that the benefits outweigh the risks. There's no evidence that chlorphenamine harms unborn babies.
You may be prescribed a short course of high-dose corticosteroid tablets, such as prednisolone, if your symptoms are severe.
Corticosteroids suppress your immune system, which lessens the symptoms of urticaria. A course of prednisolone lasting between three and five days is usually recommended.
Taking steroid tablets on a long-term basis isn't usually recommended, because it can lead to a wide range of side effects and complications, such as:
Long-term (chronic) urticaria
Treatment for chronic urticaria involves trying to control your symptoms and avoiding any triggers that make them worse.
If you have chronic urticaria and angioedema, you may be referred to a skin specialist (dermatologist). This is because angioedema is potentially more serious and can cause breathing difficulties.
You should also be referred to a dermatologist if you just have chronic urticaria and the symptoms continue, despite treatment.
Chronic urticaria is treated with antihistamines. You may have to take them regularly for as long as your symptoms last.
An increased dose may be recommended if your symptoms don't respond to treatment. Increasing the dose can often help to control symptoms that previously didn't respond to treatment. However, this should only be carried out under the instruction of the doctor in charge of your care.
Menthol cream can be used as an alternative or in addition to antihistamines because it helps to relieve itchiness. Your GP can prescribe this.
Occasionally, more serious episodes of urticaria can be treated with short doses of corticosteroid tablets, such as prednisolone. Possible side effects of corticosteroid tablets include:
Long-term use of corticosteroids for chronic urticaria isn't recommended for the reasons mentioned above.
The type of antihistamines you can get from the pharmacist are known as H1 antihistamines. However, there are several other types of antihistamines, including H2 antihistamines.
H2 antihistamines can sometimes be useful for treating chronic urticaria, because they narrow blood vessels, which can reduce the skin's redness.
H2 antihistamines can be used as an alternative to H1 antihistamines or in combination with them. Side effects of H2 antihistamines are uncommon, but include:
Don't drive or use tools or machinery if you feel dizzy after taking a H2 antihistamine.
Leukotriene receptor antagonists
Leukotriene receptor antagonists are a type of medication that can help to reduce redness and swelling of the skin.
They can be a useful long-term alternative to using corticosteroid tablets, because they don't carry the same risk of causing wide-ranging side effects.
The side effects of leukotriene receptor antagonists are rare and relatively minor. They include headaches and nausea (feeling sick).
In around two-thirds of cases, a powerful medication called ciclosporin has proved effective in treating urticaria.
Ciclosporin works in a similar way to corticosteroids. It suppresses the harmful effects of the immune system and is available in capsule form or as a liquid.
Side effects of ciclosporin include:
There are also a number of other side effects that can occur when taking ciclosporin, and you should discuss these thoroughly with your doctor before starting.
Side effects, such as high blood pressure and high cholesterol, are a particular cause for concern, because they can increase your risk of heart disease and stroke.
Even if you still respond to treatment, it may be recommended that the medication is withdrawn after a few months.
For urticaria that hasn't responded to antihistamines, there are newer medications becoming available, such as omalizumab. Omalizumab is given by injection and is thought to reduce a type of antibody that can play a part in urticaria.
There's some uncertainty over the role of diet in people with long-term urticaria. There are two groups of chemicals in foods that may trigger urticaria in some people – vasoactive amines and salicylates.
The Allergy UK website has more information on:
Avoiding or cutting down on foods that contain these chemicals may improve your symptoms. You could also keep a food diary to see whether avoiding certain foods helps you.
However, you should talk to a dietitian before restricting your diet. They can make sure you're not avoiding foods unnecessarily and that your diet is healthy.
If you know what triggers your urticaria or makes it worse, avoiding the trigger may keep your symptoms under control.
Triggers such as alcohol and caffeine can be easily avoided. If you think that a certain medication may be triggering your symptoms, contact the doctor who prescribed it, because alternatives may be available.
Avoiding stress can be more difficult, particularly if your symptoms negatively affect your quality of life.
If you have severe urticaria or urticaria that keeps coming back, you may find that relaxation techniques, such as meditation or hypnosis, reduce your stress levels and the severity of your symptoms.