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Chronic urticaria: Clinical manifestations, diagnosis, pathogenesis, and natural history

Author
Sarbjit Saini, MD
Section Editors
Bruce S Bochner, MD
Jeffrey Callen, MD, FACP, FAAD
Deputy Editor
Anna M Feldweg, MD

INTRODUCTION

Chronic urticaria (CU) is defined by the presence of urticaria (hives), on most days of the week, for a period of six weeks or longer. About 40 percent of patients with CU have accompanying episodes of angioedema [1]. No external allergic cause or contributing disease process can be identified in 80 to 90 percent of adults and children with CU [2-4]. There are several theories regarding the pathogenesis of idiopathic CU, none of which have been conclusively established. CU is a self-limited disorder in most patients, although the average duration of disease is two to five years.

The clinical manifestations, epidemiology, diagnosis, theories of pathogenesis, and natural history of CU will be reviewed here. The management of CU is discussed separately. (See "Chronic urticaria: Standard management and patient education" and "Chronic urticaria: Treatment of refractory symptoms".)

TERMINOLOGY

In this review, the term "chronic urticaria" (CU) refers to patients with isolated chronic idiopathic urticaria (CIU), as well as those with both urticaria and angioedema.

Chronic urticaria and chronic idiopathic urticaria — The terms "chronic urticaria" and "chronic idiopathic urticaria" are used interchangeably in this review and in the medical literature. These terms refer to CU in which appearance of lesions is not triggered by consistent or identifiable factors. However, physical urticaria syndromes are variably included in CU. Physical urticarias are disorders in which urticaria is induced by one or more environmental stimuli, such as heat, cold, pressure applied to the skin, exercise, water, vibration, and sunlight. The inclusion of physical urticaria in the definition of CU is based upon the observation that some patients with CU have symptoms triggered by a physical stimulus on some occasions, while most of the symptoms are spontaneous. (See "Physical urticarias" and "Cold urticaria".)

Chronic spontaneous urticaria — The term "chronic spontaneous urticaria" (CSU) is increasingly used instead of CU [5]. This term refers to CU in which appearance of lesions is not triggered by consistent or identifiable factors, and it specifically excludes the physical urticaria syndromes.

                              

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Literature review current through: Nov 2016. | This topic last updated: Tue Jan 06 00:00:00 GMT+00:00 2015.
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