Chronic idiopathic urticaria for the generalist

Abstract

Chronic idiopathic urticaria (CIU) manifests as frequently occurring, short-lived wheals, surrounded by a bright-red flare, and often accompanied by angioedema. The cause of CIU is undefined and its diagnosis requires exclusion of other conditions with somewhat similar symptoms. Recent evidence has indicated that IgG autoantibodies directed against high-affinity IgE receptors (FcϵRI) may be involved in the pathophysiology of CIU. Following the release of mast cell or basophil-derived histamine, this mediator binds to H 1 and H 2 receptors, leading to vasodilatation and increased vascular permeability. Individuals with CIU may be unable to conduct normal daily activities; therefore, prompt initiation of effective treatment is essential. General management of patients should include avoidance of substances likely to trigger or intensify episodes. Treatment with antihistamines is the mainstay of pharmacotherapy for CIU. Selection of antihistamine therapy for patients with CIU should be based on the following key properties: (1) proven clinical efficacy in providing a high rate of symptom improvement, (2) rapid onset of action and a long-lasting response, and (3) an excellent safety profile and a high degree of tolerability. The benefit of some second-generation antihistamines is limited by sedation, drug–drug interactions, or a variable therapeutic response. The H 1-receptor antagonist desloratadine is a new, once-daily treatment option that is potent and nonsedating, and has a low potential for drug–drug interactions. Desloratadine has a rapid onset of action and has been shown to effectively and safely reduce pruritus and the number and size of hives in patients with CIU, leading to improvements in quality of life.