Special Article – Clinical and Experimental Allergy
This guidance for the management of patients with chronic urticaria and angio-oedema has been prepared by the Standards of Care Committee (SOCC) of the British Society for Allergy and Clinical Immunology (BSACI). The guideline is based on evidence as well as on expert opinion and is aimed at both adult physicians and paediatricians practising in allergy. The recommendations are evidence graded. During the development of these guidelines, all BSACI members were included in the consultation process using a web-based system. Their comments and suggestions were carefully considered by the SOCC. Where evidence was lacking a consensus was reached by the experts on the committee. Included in this guideline are clinical classification, aetiology, diagnosis, investigations, treatment guidance with special sections on children with urticaria, and the use of antihistamines in women who are pregnant or breastfeeding. Finally, we have made recommendations for potential areas of future research.
This guidance for the management of patients with chronic urticaria/angio-oedema is intended for use by physicians treating allergic conditions. It should be recognized that patients referred to an allergy clinic often have a different pattern of presentation (e.g. intermittent acute) from those referred elsewhere and both the patient and referring practitioners often want to know whether allergy is involved. Evidence for the recommendations was collected by electronic literature searches using these primary keywords – urticaria, angio-oedema, epidemiology of management, drugs in chronic urticaria andangio-oedema, antihistamines. Each article was reviewed for suitability by the first and last authors of this guideline. The recommendations were evidence graded at the time of preparation of these guidelines. During the development of these guidelines, all British Society for Allergy and Clinical Immunology (BSACI) members were consulted using a web-based system and their comments and suggestions were carefully considered by the Standards of Care Committee (SOCC). Where evidence was lacking a consensus was reached among the expert son the committee. Conflicts of interests were recorded by the SOCC. None jeopardized unbiased guideline development.
Executive Summary and Recommendations
- Chronic urticaria/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.
- Urticaria and angio-oedema commonly occur together, but may also occur separately.
- Angio-oedema without urticaria is a cardinal feature 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.
- 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 personalized 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.
- 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 regime should be modified according to treatment response and development of side-effects.
- Higher than normal doses of antihistamines may be required to control severe urticaria/angio-oedema.
- If an antihistamine is required in pregnancy, the lowest dose of chlorphenamine or loratadine should be used.
- If an antihistamine is required during breastfeeding it is recommended that either loratadine or cetirizine are taken at the lowest dose.
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