Urticaria is an allergic skin condition characterised by hives or welts (raised, red, itchy lesions). Urticaria may be acute (lasts for less than six weeks) or chronic (over six weeks).

About 20 per cent of people experience urticaria at some time.

Urticaria is an allergic skin rash, caused by the release of histamine and other allergic compounds, into the bloodstream. This allergic reaction is usually in response to things like:

  • Medications (e.g. penicillin, aspirin, sulphas)
  • Foods (shellfish, fish, nuts, eggs, milk, preservatives and added chemicals, etc)
  • Pollen
  • Animal dander (especially cats)
  • Insect bites
  • Exposure to water, sunlight, cold or heat
  • Emotional stress
  • Infections (e.g. the common cold)

Please note: Almost any prescription or over-the-counter medication can cause hives. Some of those drugs include antibiotics, pain medications, sedatives, tranquillisers, and diuretics (water pills). Diet supplements, antacids, arthritis medication, vitamins, eye and eardrops, laxatives, vaginal douches, or any other non-prescription item can be a potential cause of hives. If you have an attack of hives, it’s important to tell your doctor about all of the preparations that you use to assist in finding the cause.

There seems to be a hereditary (inherited) tendency toward the development of hives. The cause is not always identified.

Chronic urticaria: the cause of this type of urticaria is usually much more difficult to identify than that of acute urticaria. In patients with chronic urticaria, the cause is found in only a small number of patients.

Skin testing for allergy, and certain blood tests, may be helpful in confirming just which substances are triggering the urticaria.
Treatment may not be needed in mild cases. The best treatment for urticaria is to find and remove the cause. This is not an easy task and often not possible (especially in chronic urticaria). Keeping a detailed food diary is often helpful.

Antihistamines are usually prescribed to provide relief. In chronic urticaria it may be necessary to take antihistamines long-term. In severe cases, urticaria may cause swelling in the mouth and airway, requiring emergency treatment to avoid total airway obstruction. Thankfully, this is quite rare.

Urticaria is rarely a dangerous condition but, especially in the chronic type, it can be a significant irritation for people.

Written by Dr Colin Burns