Urticaria - Chronic

Urticaria is caused by the release of histamine and other chemicals from cells called mast cells. Although often associated with allergies, chronic urticaria results from histamine release due to other factors that are not related to allergies.

1. Chronic spontaneous urticaria - the most common form, has no identified cause. Some medications (e.g. anti inflammatory medicines such as ibuprofen), stress, and infection can exacerbate it.
2. Chronic Inducible urticaria - when urticaria occurs after physical triggers such as cold, heat, emotion, water exposure, sunlight, pressure, or friction. 

Usually, the appearance or a description of the rash is enough for your doctor to diagnose urticaria.

There's no specific test to identify the cause, and routine allergy tests are not necessary for most people with chronic urticaria.

Antihistamines

• These include medications such as cetirizine, loratadine and fexofenadine. They block the effect of histamine, and reduce itching and the rash in most people, but may not improve it completely.
• If urticaria occurs frequently, it can be helpful to take antihistamines regularly every day.
• There are many different types including non sedating and sedating antihistamines, as well as short acting and long acting types.
• We generally recommend avoiding sedating antihistamines such as Chlorphenamine (Piriton), as these can affect school performance, concentration and sleep.
• Antihistamine tablets can be taken for as long as the urticaria persists. In some cases your doctor may advise you to take higher dose than the standard recommended dose of antihistamines up to four times the usual daily
• dose.

Oral Steroids

• These can occasionally be given as rescue treatment for severe flares of urticaria but are generally not necessary.
• Their potential side effects usually outweigh the benefits in this condition.

Topical Treatments

• For some children, calamine lotion or creams containing menthold can help iwth itching - these can be bought without a prescription. 
• Cooling the affected area with ice packs, fan and cold flannel may help too. 

Occasionally other treatments such as a medication called montelukast will be tried. 

Specialist treatments (injections) are avaliable if high doses of regular antihistamines don't work. 

Trigger avoidance (e.g. of cold water/heat) is importnat if you suffer for inducible urticaria.  Aspirin, Ibuprofen and medications containing morphine or codeine may sometimes worsen urticaria. 

The goal of treatment is to suppess symptoms until the condition naturally improves.  For most people (80%) chronic urticaria can last one to two years and them improve on it's own.  For 1 in 5 people however it lasts longer.