urticaria
Last reviewed 03/2021
Urticaria
- urticaria (also known as hives, nettle rash, or weals) is a vascular reaction of the skin (upper dermis and mucous membranes) marked by transient appearance of slightly elevated patches - wheals - which are red or pale swellings that are often attended by severe itching. Urticaria can be localised or generalised (1)
- urticaria is also used to define a disease which presents with short-lived
itchy weals, angio-oedema or both together (2)
- urticaria may be caused by many different factors including certain foods, drugs, infection, and emotional stress
- the British Association of Dermatologists has classified utricaria according
to the clinical presentation:
- ordinary urticaria
- acute (up to 6 weeks of continuous activity)
- chronic (6 weeks or more of continuous activity)
- episodic (acute intermittent or recurrent activity)
- physical urticarias - repeatedly induced by the same physical stimulant
- mechanical - delayed pressure urticaria, symptomatic dermographism
- thermal - cholinergic urticaria, cold contact urticaria
- other - solar urticaria, aquagenic urticaria
- angio-oedema without weals
- idiopathic
- drug induced
- C1 esterase inhibitor deficiency
- contact urticaria - contact with allergens or chemical
- urticarial vasculitis - defined by vasculitis on skin biopsy
- autoinflammatory syndromes
- hereditary
- acquired (2)
- ordinary urticaria
- two or more types of urticaria can occur at the same time in a patient (1)
- urticaria is frequently accompanied by angioedema (3)
Click here for images of urticarial rash
Reference:
- 1. Clinical Knowledge Summaries 2007. Urticaria
- 2. British Association of Dermatologists 2007. Guidelines for evaluation and management of urticaria in adults and children
- 3. American Academy of Emergency Medicine 2006. Clinical Practice Guideline: Initial Evaluation and Management of Patients Presenting with Acute Urticaria or Angioedema