Urticaria goes by several names, including hives, nettle rash and welts. It is an itchy red rash composed of weals that affects the skin. These can vary greatly in size, from just a few millimetres to a handspan. Generally, an outbreak of urticaria will be over within 24 hours and when the weals fade the skin returns to normal. The condition can be either acute or chronic, the latter label being given when an outbreak strikes daily for six weeks. An estimated 1 in 5 people will be affected by acute urticaria at some point in their lives, though it is more common amongst children. Chronic urticaria will only affect about 1 in 1000.
With acute urticaria, allergens, irritants, infections, medicines or physical factors like heat or exercise can spark the condition. An allergen could be a certain food or material the body reacts to, whilst an irritant may be something like a nettle sting. Any of these factors may trigger the release of histamine in the skin, which is what causes the swollen itchy weals. Nonetheless, sometimes no cause can be identified. Chronic urticaria is linked to other conditions, such as autoimmunity problems. For example, if the immune system attacks the cells that contain histamine this will be released, causing urticaria. Other conditions have been linked to chronic urticaria, including thyroid disease and viral hepatitis.
Depending on what a doctor believes the cause of urticaria to be, you may be referred to an allergy clinic. In some cases urticaria clears of its own accord, however antihistamines are a common treatment for the condition. Corticosteroid tablets are also sometimes prescribed and menthol cream can be used to relieve itching. A change in diet is sometimes recommended to sufferers of chronic urticaria.
More complicated forms of urticaria exist, such as urticaria vasculitis, which leaves a bruise and requires a dermatologist’s expertise. Angioedema may also occur, causing swelling with a burning sensation, usually around the eyelids and lips. This will normally clear in a few days but call your GP if symptoms persist or cause difficulty with breathing.
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