Urticaria is characterized by the development of hives, angioedema, or both. Three common features are seen in all cases of hives; swelling and erythema; itching/burning sensations and transient nature with the skin returning to normal appearance within 1-24 hours.

The prevalence of chronic urticaria in the general population ranges from 0.5 to 5%, with its incidence estimated at 1.4% per year in the western world. The prevalence of chronic urticaria is significantly higher in women than men with the average age of onset being 40 years.

Acute (<6 weeks) and chronic (>6 weeks) urticaria are two major types of urticaria. The challenge with the management of chronic urticaria is that the hives or angioedema sometimes appear spontaneously resulting from unidentified causes or pathophysiology which is not completely understood. As of now, the only identified precipitating factor is non-steroidal anti-inflammatory drugs. Owing to their spontaneous remissions, it is extremely difficult to articulate a cause-effect relationship.

Due to the central role played by mast cells and histamine in the pathophysiology of the disease, H1-antihistamines continue to be the first line treatment. However, recent knowledge about the disease has identified the significant role for T-lymphocytes, B-lymphocytes, and autoantibodies in the pathophysiology of the disease. Implications of these other mediators have provided potential future targets for treatment.

Some patients have antibodies against a high affinity receptor for IgE that can stimulate and activate mast cells. This is clinically important, since in treatment resistant patients, immunomodulatory treatments are potentially valuable. Even though the patients with autoantibodies do not have any distinguishing diagnostic clinical features, still they tend to have more severe urticaria. Agents such as omalizumab previously used to treat other autoimmune and inflammatory diseases have shown efficacy in chronic spontaneous urticaria and are potential therapeutic alternatives for antihistamine unresponsive patients.