Urticaria and angioedema

摘要

Urticaria, also known as hives, may affect up to 20% of the population at some time. Urticaria is described as pruritic erythematous, raised, circumscribed lesions with central pallor that blanch with pressure. Urticaria is closely associated with angioedema in 40% of individuals; approximately10% of patients experience angioedema without urticaria. Urticarial lesions often are generalized, with multiple lesions in no specific distribution; angioedema tends to be localized and commonly affects the face (periorbital and perioral regions) or tongue. Urticaria is subdivided into acuteand chronic urticaria based on the duration of symptoms. Acute urticaria lasts 6 weeksis designated as chronic urticaria, and an etiology is seldom identified and thus considered spontaneous. Chronic urticaria may have an autoimmune basis. There is a well-documented association between autoimmune hypothyroidism (Hashimoto disease) and urticaria and angioedema, with a higherincidence of antithyroid (antithyroglobulin and antiperoxidase) antibodies in these patients, who are usually euthyroid. Furthermore, results of studies revealed a circulating immunoglobulin G (IgG) antibody directed against the high affinity IgE receptor alpha subunit IgE receptor (FcεRI)or IgE in 40‐60% of patients with chronic urticaria. A stepwise approach to the treatment of urticarial is recommended with second-generation H1 antihistamines being the first line of therapy.