Management of chronic urticaria and angioedema

Standards of Care Committee, British Society for Allergy and Clinical Immunology


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Definition

  • Chronic urticaria/angioedema has traditionally been defined as weals, angioedema or both with daily or almost daily symptoms lasting for more than 6 weeks. In these guidelines, we have also included patients with episodic acute intermittent urticaria/angioedema lasting for hours or days and recurring over months or years
  • Weals and angioedema commonly occur together, but may also occur separately
  • Chronic urticaria affects 2–3% of individuals (lifetime prevalence) and significantly reduces quality of life (QoL)

Aetiology

  • Urticaria may occur alone in about 50% of cases, urticaria with angioedema in 40%, and angioedema without weals in 10%
  • Aetiological classification of chronic urticaria/angioedema:
    • spontaneous/idiopathic (40–50% cases)
    • autoimmune
    • physical stimuli (triggers include exercise, exposure to cold or heat)
    • drug induced
    • infection (e.g. parasites, Epstein–Barr virus, hepatitis B and C)
    • allergic (associated with latex, grass, animals, food)
    • C1 inhibitor deficiency:
      • genetic
      • acquired
    • non-IgE-mediated mast cell degranulation (can be triggered by opiates)
    • vasculitis
    • food constituent (rare; triggers include salicylates/benzoates)
  • Autoimmune urticaria/angioedema accounts for about 50% of chronic urticaria and may be associated with other autoimmune conditions such as thyroiditis
  • Angioedema without weals is the hallmark of hereditary angioedema (HAE) and typically involves subcutaneous sites, gut, and larynx. In HAE, levels of C4 and C1 inhibitor (functional or antigenic) are low
  • 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. Investigations may include:
    • full blood count
    • urinalysis
    • erythrocyte sedimentation rate and/or C-reactive protein
    • thyroid function and thyroid autoantibodies
    • challenge testing
    • skin prick tests
    • skin biopsy (to exclude vasculitis)
  • 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/angioedema if there is no temporal relationship to a particular food trigger, either by ingestion or contact. Food additives rarely cause chronic urticaria and angioedema
  • Certain drugs (e.g. non-steroidal anti-inflammatory drugs) can cause chronic urticaria and/or angioedema and hence a detailed drug history is mandatory
  • Angiotensin-converting enzyme (ACE) inhibitors can cause angioedema without weals resulting in airway compromise. They should be withdrawn in subjects with a history of angioedema. ACE inhibitors are contraindicated in individuals with a history of angioedema with or without weals

Treatment

  • Autoimmune and some inducible weals 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 and higher doses may be appropriate
  • 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 angioedema
    • omalizumab:
      • used for chronic urticaria when higher dose antihistamines have failed to control symptoms
    • ciclosporin:
      • may be considered in severe unremitting disease uncontrolled by antihistamines; requires close patient monitoring

Algorithm for diagnosis of chronic urticaria and/or angioedema*

Algorithm for diagnosis of chronic urticaria and/or angioedema
* Spontaneous urticaria ± angioedema: accounts for 40–50% of cases
† Other individuals who may need referral include those patients who are pregnant or lactating, and children where there is parental anxiety, or if school or work is being affected

Reasons for referral to specialist

  • These include:
    • cases of diagnostic uncertainty
    • urticaria and/or angioedema where it is important to exclude an allergic cause
    • a patient who is symptomatic despite treatment with regular antihistamines
    • angioedema that is persistent, recurrent, or affecting the airway
    • abnormal C4 ± C1 inhibitor deficiency in the presence of angioedema alone without urticaria
    • possibility of vasculitic urticaria
    • a pregnant or breast-feeding woman who requires treatment
    • children, if schooling is affected

References

full guideline available from...

Standards of Care Committee, British Society for Allergy and Clinical Immunology

www.bsaci.org

Powell RJ, Leech SC, Till S et al. BSACI guideline for the management of chronic urticaria and angioedema. Clinical and Experimental Allergy 2015; 45: 547–565.


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