What are hives?

Hives (technically known as urticaria) are a skin condition characterized by an itchy, raised red lesion, usually with distinct borders. An individual lesion may be referred to as a wheal.

Hives are skin rashes and welts.

What causes hives?

There are many potential causes of hives. Some will be discussed in detail here. Regardless of the trigger, there is a release of chemicals such as histamine in the skin. This causes the blood vessels to become leaky, and swelling is visible. Superficial nerves in the skin may become irritated, therefore causing an itching sensation.

Allergic causes of hives

Allergic causes of hives usually last less than six weeks. Food allergies fall into this category. The effects may start within minutes of contact with the substance and can last for weeks. Common offenders include soy, nuts, shellfish, and eggs. Your dermatologist can help you determine the cause of allergic urticaria.

Non-allergic causes of hives

Some medical illnesses may cause hives. Certain viral illness, more common in children, may cause hives. These are usually short lived rashes that will resolve when the underlying viral illness disappears. Certain medications such as penicillin, sulfa containing medications, aspirin, and certain seizure medicines are commonly associated with causing hives.
Physical urticarias are characterized by the agent that comes into contact with or stimulates the skin-eiter directly or indirectly. Things such as hot or cold water or air, exercise and intense sunlight, and even pressure from clothing and undergarments.

How are hives treated?

The treatment of hives depends on the cause. The allergic or acute causes are often treated with observation. Your dermatologist will try to help you determine the cause, so that the offending agent can be avoided. Your Dermatologist may prescribe antihistamine medications or steroids. These can be applied topically or taken orally.
Chronic hives (lasting longer than six months) are more difficult to treat. The same types of medications may be tried, but in some cases are ineffective. Some patients may respond to certain anti-depressant medications such as doxepin. For other patients, education and trigger avoidance are all that can be done.

With any case of hives, it is important to work with your Dermatologist to help determine the cause and make sure it will not progress to a more serious allergic condition that may affect your breathing.