Urticaria

Urticaria is also known as nettle rash. The most common feature of Urticaria is the appearance of red rash on the surface of the skin. The rashes are due to allergic reactions. The allergen causes the body to release histamine. The histamine causes the leakage of capillaries. The fluid accumulates in skin leading to the occurrence of rash.
Some of the common allergens include anti inflammatory drugs and chemicals.
Physical factors such as low temperature, sunlight, water can also cause allergic reactions.
If the rash lasts for more than six weeks it is referred to as chronic uritcaria. It is a rare condition and affects only one in 1000 people.
Anaphylaxis can be a life threatening condition and one of the first symptoms anaphylaxis is the uritcaria.

Symptoms

The rashes are almost always red or pink in colour. They are round or oval in shape and there size varies. The rashes are also associated with swelling and are referred to as wheals.
New wheals replace the old ones every few hours.

Symptoms of anaphylaxis include:

• Difficulty in breathing.
• Vomiting and nausea.
• Swelling of lips and tongue.

Causes

Acute uritcaria is caused by the release by histamine which ultimately leads to formation of rashes.
Some of the known allergens are food items such as egg, nuts, chocolates, citrus fruits.
Certain medicines, physical factors such as sunlight, water.

Chronic uritcaria on the other hand are not caused by these allergens. It is usually caused by autoimmune reactions.

Some of the other causes of chronic uritcaria are thyroid diseases and other chronic illness. Intestinal parasites can also cause chronic uritcaria.

Diagnosis

the first step in the diagnosis step is the examination of rashes. The next step would be to find the allergen. Identifying the allergen helps in proper treatment.
In some of the cases the cause is never identified.

In chronic cases allergy tests are not performed since it is highly unlikely that the reaction is due to allergen. However substances that can make it severe are identified which helps in treatment.

Some of the tests that are performed to find the causes of chronic uritcaria are:

• Blood count test.
• Stool sample test which can identify intestinal parasites.
• Erythrocyte sedimentation rate test which helps identifying problems with immune system.
• Thyroid function test.
• Liver function test.

Treatment

Symptoms of acute uritcaria are mild and do not require any treatment.
Antihistamines are used for the treatment if the condition is more serious.
Anti histamines are replaced with Chlorphenamine in pregnant women.

If the symptoms are more severe, corticisteroids are used.

Treatment for chronic uritcaria includes administering antihistamines and carticosteroids. Methanol cream can also be applied.

Prevention of uritcaria

Some of the common triggers of chronic uritcaria are alcohol, caffeine and some of the medications. It is important to identify and avoid these triggers.

Certain food items can increase the production of histamines. They are:

• Spinach.
• Yoghurt.
• Fish products.
• Chocolates.
• Strawberries.

It is important to maintain a food diary which helps identify and avoid those food items in diet.