The condition and the treatment
Urticaria (also called hives) is a raised, itchy rash. It is chronic if it lasts on and off for at least 6 weeks. The rash can affect 1 part of the body or can spread across large areas. Some people sometimes also develop swelling of the lips, tongue or other areas of the body. With spontaneous urticaria, the symptoms are thought be caused by the immune system mistakenly attacking healthy tissue. Antihistamines and leukotriene receptor antagonists are types of drugs used to treat the symptoms of urticaria.
Omalizumab (Xolair) works by blocking the action of IgE. This is a substance that plays a part in the immune system and is thought to cause the symptoms of urticaria.
NHS Choices (www.nhs.uk) may be a good place to find out more.