Urticaria is an itchy, lumpy, red rash, often called hives, wheals or nettle rash.
Angioedema is swelling, often of the face or lips. Over half of patients with urticaria will also have angioedema. Less frequently angioedema occurs without urticaria.
Dermographism is when your skin is very sensitive and will show a red raised rash by rubbing.
Acute urticaria is a rash that lasts for up to six weeks. It may be due to an allergy if it lasts a day or two. Urticaria caused by allergies can recur on repeated exposure, in which case it is called Acute Intermittent Urticaria. If the rash persists for a few days to a few weeks, the usual trigger in children is a viral infection rather than an allergy.
Chronic urticaria lasts more than six weeks. Individual spots last less than 24 hours and occur most days. It affects 1 in 200 children. Chronic urticaria is not associated with severe allergic reactions (anaphylaxis) and adrenaline autoinjector is not required. However, it can impact on quality of life by causing difficulty sleeping and problems concentrating at school.
Chronic urticaria is not an allergy. Some children can have urticaria triggered by cold, heat, sunlight, exercise, scratching, rubbing (see photo of dermographism) and even stress. Often no cause can be found, in which case it is called idiopathic urticaria.
In adults, the most common cause of angioedema is ibuprofen or ACE inhibitors such as enalapril. Patients on ACE inhibitors should see their doctor, who may consider alternatives.
If your child only gets angioedema but not urticaria, it is important to make sure that these medicines are avoided.
The diagnosis is made on the history and pattern of the rash. No tests are usually needed. In a small minority where individual spots last more than 24 hours or there is associated bruising your doctor may consider investigating for other causes.
If the rash is made worse by specific triggers, these should be avoided if possible. For instance, if hot showers bring out the rash, lukewarm water should be used for washing.
A regular dose of a non-drowsy antihistamine (e.g. cetirizine, loratadine) is the treatment of choice. It may need to be taken up to four times the licensed dose daily for many months or years.
Other treatments may be suggested by your doctor if regular use of the antihistamines do not control your child’s symptoms. Steroids are not recommended.
Forty percent of children will be disease free after one year and 70% after four years. Chronic Urticaria will not lead to airway closure, wheeze, or severe allergic reaction.