Urticaria: Symptoms and Treatment

Can the sun cause urticaria (hives)?

Solar urticaria (hives)

Yes, solar urticaria is a physical urticaria caused by sunlight. Hives may appear within a few minutes after exposure to the sun and fade within a few hours.

What is urticaria?

Urticaria is another name for hives or the wheals that form on the skin, as the result of an allergic reaction to something. Sometimes, the allergen which causes a reaction can be identified immediately, but not always.

What happens when a person has an allergic reaction?

Blood plasma leaks between the cells.
Histamine is released from the mast cells along the blood vessels.
The formation of wheals (hives) occurs upon the skin.

What does urticaria look like?

The symptoms of urticaria or hives may vary depending upon the cause, but hives should be taken seriously, as they can be frightening for the person who is affected and may present a life threatening experience. 

Emergency medical treatment at a hospital or by a physician may be required if the symptoms are severe.

Symptoms:

Symptoms of urticaria may include the following: localized wheals (or swellings known as hives) form individually or in groups. Wheals are pale in color, itchy and may burn or sting. Wheals may be different sizes, pencil diameter to plate size. New wheals may develop as old ones fade. Wheals may join together to form one large hive. Urticaria may cause swelling of eyes, lips or genitals. There may be difficulty breathing or swallowing and wheezing, flushng or fainting.

What is the actual incidence of hives?

Hives affect approximately 10-20% of the population, at one time or another in their lives, according to the 

Amercian Academy of Dermatology.

How long will the hives persist?

Acute urticaria will last anywhere from a few days to a few weeks. Any urticaria that persists longer than that would be referred to as chronic urticaria.

Causes of urticaria::

Foods: nuts, chocolate, shellfish, tomatoes, eggs, berries, milk, food additives and preservatives
Drugs: medication eg. antibiotics, diuretics, vitamins, pain medications etc.Infections: viral, (colds in children), bacterial or fungal

Insect bites
Internal diseases: hepatitis or liver disease
Physical causes: sunlight, heat, cold, water, vibration or exercise

Treatment of urticaria may include the following: identify and eliminate the cause if possible, antihistamines, epinephrine (adrenalin) injection and cortisone

Urticaria and liver disease

Hepatitis is one of the diseases known to cause hives.

Chronic urticaria

Chronic urticaria that persists over six weeks may have a cause that is difficult to identify. A further investigation may be required including a physical examination, questioning re possible allergens and blood work to rule out any possible disease processes. A biopsy may be indicated.

http://www.aad.org/public/publications/pamphlets/skin_urticaria.html