Management of chronic urticaria and angio-oedema

• British Society for Allergy and Clinical Immunology •

Definition

• Chronic urticaria (‘hives’ or ‘nettle rash’)/angio-oedema has traditionally been defined as daily or almost daily symptoms lasting for more than 6 weeks. In these guidelines we have also included patients with episodic acute intermittent urticaria/angio-oedema lasting for hours or days and recurring over months or years

Clinical classification

• Urticaria and angio-oedema commonly occur together, but may also occur separately
• Angio-oedema without urticaria is the hallmark of hereditary angio-oedema (HAE) and typically involves subcutaneous sites, gut, and larynx. In HAE levels of C4 and C1 inhibitor (functional or antigenic) are low
• Chronic urticaria affects 0.5–1% of individuals (lifetime prevalence) and significantly reduces quality of life (QoL)
• Autoimmune urticaria/angio-oedema accounts for about 30–50% of chronic urticaria and may be associated with other autoimmune conditions such as thyroiditis
• There are important differences in aetiology and management in children compared with adults

Diagnosis

• The diagnosis is based primarily on the clinical history. Investigations are determined by the clinical history and presentation, but may not be necessary
• Management must include the identification and/or exclusion of possible triggers, patient education and a personalised management plan
• Food can usually be excluded as a cause of urticaria/angio-oedema if there is no temporal relationship to a particular food trigger, either by ingestion or contact. Food additives/preservatives/dyes do not cause chronic urticaria and angio-oedema by an IgE-mediated mechanism
• Certain drugs can cause chronic urticaria and/or angio-oedema and hence a detailed drug history is mandatory
• Angiotensin-converting enzyme (ACE) inhibitors can cause angio-oedema without urticaria resulting in airway compromise. They should be withdrawn in subjects with a history of angio-oedema

Treatment

• Autoimmune and some physical urticarias are more resistant to treatment and can follow a protracted course
• Pharmacological treatment should be started with a standard dose of a non-sedating H1 antihistamine
• The treatment regimen should be modified according to treatment response and development of side-effects
• Additional pharmacotherapy should be considered after consultation with a specialist:
  • leukotriene receptor antagonists (e.g. montelukast, zafirlukast):
    • may be considered in autoimmune urticaria and chronic urticaria with positive challenge to aspirin
  • tranexamic acid:
    • useful off-licence in the treatment of angio-oedema
  • ciclosporin:
    • used with variable success in specialist centres and requires close patient monitoring