Helpline
Chronic spontaneous urticaria (CSU) leaflet
A practical guide to understanding and managing Chronic Spontaneous Urticaria (CSU), including symptoms, diagnosis, treatment options and tips for getting the most from healthcare appointments.
Types of urticaria and hives
The many different clinical forms of urticaria and they can be divided according to their duration into acute (less than six weeks) and chronic (more than six weeks) and other.
Acute spontaneous urticaria
- The most common form of urticaria is acute urticaria or “acute spontaneous urticaria”, which lasts a maximum of six weeks (usually a few days to three weeks) and is usually easy to treat. In some patients, angioedema (swelling of deep skin) also occurs. Severe acute spontaneous urticaria may also be accompanied by fever, headache, diarrhea, difficulty in breathing and swallowing, joint pain, and tiredness/fatigue.
Chronic spontaneous urticaria
- If urticarial symptoms – redness, hives, and itching – persist longer than six weeks, it is called chronic spontaneous urticaria.
Other types of urticaria include;
- Urticaria factitia can be caused by rubbing, scratching, or scrubbing the skin.
- Cold urticaria occurs when there is contact between the skin and cold.
- Heat urticaria occurs when contact between the skin and warmth/heat.
- Solar urticaria is caused by UV light or sunlight.
- Pressure urticaria presents with swelling at sites of pressure.
- Aquagenic urticaria occurs when there is contact between the skin and water.
- Cholinergic urticaria presents where contact between the skin and raised temperatures (for example hot baths) occurs.
- Exercise-induced urticaria/anaphylaxis occurs during instances of physical strain.
Symptoms of urticaria
Urticaria can appear suddenly, often without warning. You may wake up one morning to find red, raised welts on your skin, or they may develop rapidly throughout the day. The welts associated with urticaria are usually accompanied by intense itching. This itching can be so severe that it becomes difficult to focus on anything else, and scratching may provide only temporary relief.
The main symptom of hives is an itchy rash and the rash can appear as;
- Raised bumps or patches in many shapes and sizes.
- Appear anywhere on the body.
- Be on one area or spread across the body.
- Feel itchy, sting or burn.
- Look pink or red when affecting someone with white skin; the colour of the rash can be harder to see on brown and black skin.
How is urticaria currently diagnosed?
Chronic spontaneous urticaria (CSU) can be diagnosed with a detailed patient history. A GP will usually ask a patient to keep a symptom diary to record any potential triggers in order to exclude or confirm a diagnosis of CSU. It is important to record the onset, duration and course of CSU. The duration of the individual wheals and rash should also be recorded accurately. Any occurrence of angioedema should be noted. Further tests may include evaluations of the skin, blood and urine. If initial treatment is ineffective, GPs should refer patients to see a specialist dermatologist or immunologist for further treatment.
See a GP if;
- the symptoms do not improve after two days
- you’re worried about your child’s hives
- the rash is spreading
- hives keeps coming back – you may be allergic to something
- you also have a high temperature and feel generally unwell
- you also have swelling under the skin – this might be angioedema
A GP may prescribe menthol cream, stronger antihistamines or steroid tablets. If your urticaria does not go away with treatment, you may be referred to a skin specialist (dermatologist).
What is angioedema?
Angioedema is another skin allergy and is the name given to deeper swelling affecting the skin over the arms, legs, torso, or face. It may also affect the tongue, mouth, throat and sometimes the upper airway. These swellings commonly last for more than 24 hours, and usually there is no itching. It is not possible to identify an underlying cause for angioedema in the vast majority of cases.
Urticaria and angioedema often occur at different times or together in the same person. They occur in about 15 percent of the population at some time or other in their lives, with women more commonly affected than men.
Allergic angioedema is triggered by an allergic reaction to certain foods, medications, insect stings, or other allergens. It is often associated with hives (urticaria) and can be life-threatening if it affects the throat or airways, leading to difficulty breathing or swallowing.
Symptoms of angioedema typically include swelling, often with redness or warmth in the affected area. The swelling may be accompanied by itching or a burning sensation. In severe cases, particularly when angioedema affects the throat or airways, it can lead to difficulty breathing, swallowing, or speaking, which requires immediate medical attention.
