The cause of urticaria should be removed or treated if it is possible to find one. Unfortunately, this is often not the case, particularly in chronic urticaria. Some of these patients appear to have an autoimmune disease. Others are caused by infections and a few may be caused by dietary intolerance but the rest are said to have ‘idiopathic’ urticaria when a cause for it cannot be found. In about 20% of patients with chronic urticaria a reproducible physical trigger can be confirmed by testing even though the underlying reason for this remains unknown. Avoidance of this trigger can help to alleviate the symptoms of the condition.
Similarly, it is often possible to identify aggravating factors that make spontaneous urticaria worse even if they have not caused it in the first place. These may include aspirin or other medicines, dietary intolerance, upper respiratory tract infections, overheating, tight clothing and even stress. Minimizing exposure to these aggravating factors may make it easier to control urticaria with medicines. Antihistamines are the best treatment for many patients because they are safe and effective for itch and the swellings. Taking a higher dose than usual can help some patients more than others.
Very severe urticaria is sometimes treated with short courses of steroid tablets or a steroid injection while steroid creams do not usually work. Side effects from steroids tablets are predictable after a few weeks or months and may be severe so long term continuous use should be avoided. Fortunately there are several other medicines that can be taken when antihistamines do not work well, including some that suppress the hyperactive immune system that causes autoimmune urticaria.