How do dermatologists diagnose hives?
When a patient has hives on the skin, a dermatologist can often make the diagnosis by looking at the skin. Finding the cause of hives, however, can sometimes be hard. This is especially true for hives that have been around for more than six weeks.
To find out what is causing your hives, your dermatologist will review your health history, ask questions, and do a physical exam. You may need the following tests:
- Allergy tests (on the skin or blood tests).
- Blood work (to rule out an illness or infection).
- A skin biopsy.
To perform a skin biopsy, the dermatologist removes a small piece of affected skin so that it can be examined under a microscope.
How do dermatologists treat hives?
For a mild or moderate case of hives, the most common treatment is a non-sedating (does not cause drowsiness) antihistamine. Antihistamines relieve symptoms like itching.
If you have chronic hives, your dermatologist may prescribe an antihistamine. You should take this medicine every day to prevent hives from forming. There are many antihistamines on the market. Some make you drowsy, and some do not. No one antihistamine works for everyone. Your dermatologist may combine an antihistamine with other medicines to control the hives.
Other medicines that are prescribed to treat hives include:
- Cortisones (for short-term use only because of side effects with long-term use).
- Dapsone, an antibacterial.
- Other medicines that fight inflammation (redness and swelling).
Ask your dermatologist about possible side effects (health problems that can result from the medicines).
For some cases of hives or angioedema, you may need an injection of epinephrine (shot of adrenaline).
A hive often will go away in 24 hours or less, but bouts can last longer.
A few people have chronic hives (lasting more than six weeks). Sometimes chronic hives go away on their own — often within a year. For others, hives can come and go for months or years. Children may outgrow the allergies that cause their hives.
For most people, hives are not serious. In some people, though, hives may be a sign of an internal disease. Others can get a severe swelling with hives known as angioedema. If you have hives and trouble breathing or swallowing, get emergency care right away.
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