Urticaria results from the release of histamine, bradykinin, leukotriene C4, prostaglandin D2, and other vasoactive substances from mast cells and basophils in the dermis. These substances cause extravasation of fluid into the dermis, leading to the urticarial lesion. The intense pruritus of urticaria is a result of histamine released into the dermis.
The prevalence of chronic autoimmune urticaria in Singapore is similar to that reported in Western countries at about 42%.
Antihistamines are the most helpful. Over-the-counter antihistamines, such as Benadryl, are helpful, but often cause side effects, such as drowsiness. Some of the newer prescription antihistamines can help without causing any side effects.
The autoimmune antibody study aims at learning more about the biology of urticaria by studying the antibodies produced in some of the patients, and the receptors they bind to, on the skin cells. Patients with longstanding urticaria, who do not have any identifiable trigger for their symptoms, are enrolled in the study on a volunteer basis and a sample of blood is drawn for investigative purposes.