Skin – Urticaria and Angioedema
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Hives are reddish pink swellings or “wheals” that occur in crops on any part of the skin. Each wheal lasts a few hours before fading away, leaving no trace. New hives may continue to develop as old ones fade. They can vary in size from as small as a pencil eraser to as large as a dinner plate and may join together to form larger swellings. Hives are usually very itchy, but may also burn or sting.
A natural chemical substance called Histamine is released from cells called “mast cells” which are found in the skin. A number of different things including allergic reactions, chemicals in foods, or medications can cause histamine release.
Hives usually disappear within a few days to a few weeks. Occasionally, a person will continue to have hives for many years. When hives form around the eyes or lips, the tissue may swell excessively. The term Angioedema is used to describe this type of swelling.
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Acute Urticaria |
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Foods |
Hives may appear within minutes or up to two hours after eating offending food(s).
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Drugs |
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Infections |
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Chronic Urticaria |
Since there are no specific tests to determine the cause of hives, testing will vary depending on one’s medical history and findings on clinical examination by the doctor.
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Physical Urticarias |
Cholinergic urticaria is tiny bumps surrounded by a white or red halo which come on with exercise, heat or emotion. These bumps itch intensely. Anything which raises the skin temperature can cause these tiny hives – sweating, sunlight, hot baths, blushing or anger.
The most common of the physical urticarias is called Dermatographism. Hives form from firmly stroking or scratching the skin. These hives may be very itchy.
Cold Urticaria [read more]
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Treatment |
The ideal treatment for hives is to determine cause and then eliminate it. Unfortunately, this is not always an easy task. While investigating the cause of hives, or when a cause cannot be found, antihistamines are usually prescribed by your dermatologist to provide some relief. Antihistamines work best if taken on a regular schedule to prevent hives from forming.
Antihistamines have previously been prescribed to take at night. But because of the side-effect of causing drowsiness, new less-sedating antihistamines are now available. The advantage of these new antihistamines is that they can be taken during the day without causing drowsiness.