Chronic idiopathic urticaria

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Synonyms and keywords: CIU

Chronic idiopathic urticaria (CIU) is defined as frequent (daily, or near daily) itching and wheals for 6 weeks or more in the absence of any known cause. The incidence is approximately 0.5% of the population.

There are 2 subgroups of patients.

30%-50% of patients have IgG autoantibodies against either the high-affinity IgE receptor FcεR1 or, less commonly, IgE. These patients also have an increased risk of antithyroid autoantibodies. Establishing this diagnosis is helpful as these patients may benefit from immunotherapy.

In 50% of patients no autoantibodies are detected.

About 90% of patients also have angioedema.

There are no convenient readily available diagnostic studies.

Template:WH

Template:WS