Chronic urticaria--assessment and treatment

Chronic urticaria is a common condition encountered in general practice and a frequent source of referral to the clinical immunologist, allergist and dermatologist.

This article discusses the assessment and management of chronic urticaria in the general practice setting.

Chronic urticaria is defined as the occurrence of transient wheals lasting more than 6 weeks in duration. In 80% of cases, a cause is not identified and this is classified as chronic idiopathic urticaria. A physical trigger, vasculitis or systemic disease account for a smaller proportion of cases. Allergic causes are rarely responsible. A detailed history provides the most useful information in determining the presence of chronic urticaria and a possible aetiology. Apart from thyroid function tests and thyroid autoantibodies, other investigations should only be performed if clinically indicated. Second generation antihistamines are the mainstay of treatment and usually twice daily regimens are required for adequate control. H2 antagonists, doxepin and immunomodulation may be necessary in some patients.