Chronic spontaneous urticaria

Urticaria is considered common and can affect one in five people at some stage in their life. 

Urticaria occurs when mast cells are activated and release histamine and other inflammatory signalling chemicals. 

Mast cells can be activated by various triggers, including: 

• Autoimmunity: the body produces autoantibodies (antibodies which attack one’s own cells), which bind to immunoglobulin E receptors (IgE) on mast cells. Autoimmune conditions, such as systemic lupus erythematosus, Grave’s disease (auto-immune thyroid disease), and rheumatoid arthritis, may predispose patients to urticaria. Research has demonstrated that at least 50% of patients with chronic spontaneous urticaria have an autoimmune condition.
• Medicines-induced, e.g. NSAIDs (non-steroidal anti-inflammatory drugs such as ibuprofen and naproxen)
• Recreational drugs may lead to urticaria
• Atopic eczema and asthma.
• Infectious causes: bacterial or viral may lead to the start of, or the exacerbation of, CSU (for example covid-19 virus, mycoplasma pneumoniae, hepatitis viruses, helicobacter pylori)

The release of histamine activates nerves in the skin, causing enormous itching, vasodilation (blood vessels expand, and therefore there is redness), plasma extravasation (release of blood fluid components into surrounding tissues, and therefore swelling of the skin) and immune cell recruitment to the lesions (which can make the urticaria last for longer). 

• Itch
  • It’s the itch which is really awful
  • The itch can be worse at night, but this can be because our attention is occupied during the day, and we don’t notice the extent of the itch
  • Sometimes the itch can keep you awake at night
  • Some patients even think of suicide because the itch is so bad. If you are one of those patients who feel like you have had enough, or are thinking of harming yourself please do seek medical help immediately from the local A&E dept
• Weals:
  • Raised bumps/patches on the skin
  • Few millimetres to centimetres in size
  • Itchy/ burning/ painful weals
  • Skin-toned or red in colour
  • In darker skin tones, post-inflammatory pigmentation may develop causing the affected area to darken.
• Angioedema:
  • Swollen eyes/cheeks/lips
  • Swollen tongue/ oral mucosa
• Systemic:
  • Headache
  • Fatigue
  • Joint pain
  • Joint swelling
  • Wheeze
  • Palpitations
  • Flushing
  • Stomach issues

What does chronic spontaneous urticaria look like? 

Images Skin Deep. 

Chronic spontaneous urticaria is diagnosed based on the history of symptoms and physical examination. 

The history may explore:

• Duration of symptoms
• Weals: size, shape, frequency, how long each weal lasts
• Angioedema: frequency, sites
• Systemic symptoms (what else is going on with the rest of the body)
• Infective symptoms
• Other medical conditions
• Family history: weals, angioedema, allergies, autoimmune disease
• Social history
• Occupational history
• Drug history
• Dietary changes 

If there is a suspected underlying cause, then blood tests may be required. 

Allergy testing is not routinely involved in investigating chronic spontaneous urticaria.

How can chronic spontaneous urticaria be treated? 

There is no cure for chronic spontaneous urticaria, instead treatment aims to minimise the occurrence and severity of symptoms. 

This may involve identifying and mitigating triggers. 

Pharmacological management includes: 

Will I need an Epipen?

No.

Is it related to my diet?

Almost always no. But alcohol may exacerbate CSU.

If you are worried about CSU speak with your GP or someone in your GP surgery. Please do not just think it will go away. Do seek help. 

Written by Professor Anthony Bewley, Consultant Dermatologist & Dr Nafisa Islam.

With thanks to Novartis for supporting this content.