aka hives

Release of histamine and other pro-inflammatory cytokines by mast cells.

May be associated with angioedema and flushing of the skin - can be acute or chronic

Causes

Exogenous interactions

  • Allergies to food, medications or animals
  • Contact with chemicals, latex or stinging nettles
  • Medications
  • Viral infections
  • Insect bites
  • Dermatographism (rubbing of the skin)

Chronic urticaria

Can be with or without a trigger. Triggers can be

  • Sunlight
  • Temperature change
  • Exercise
  • Strong emotions
  • Hot or cold weather
  • Pressure (dermatographism)

Management

Antihistamines are the main treatment for urticaria. 

Fexofenadine is usually the antihistamine of choice for chronic urticaria. 

Oral steroids may be considered as a short course for severe flares.

In very problematic cases referral to a specialist may be required to consider treatment with:

  • Anti-leukotrienes such as montelukast
  • Omalizumab, which targets IgE
  • Cyclosporin