Hives

Medical Dermatology

Urticaria is the medical term for hives. They are pink welts or swellings that can itch, burn, or sting. These rashes can vary in size from as small as a pen tip to as large as a dinner plate, and may join to form even larger swellings.

They often will disappear within a few hours. Some may last a few days or recur continuously over months or years. New hives may develop as old ones fade.

They can appear on any part of the skin. When they form around the eyes, lips, or genitals, swelling may be more than normal. Although frightening, the swelling usually goes away in less than 24 hours. Severe cases of hives may cause difficulty breathing or swallowing. If this occurs, seek immediate emergency care.

Anyone can get these rashes. Approximately 10 to 20% of the population experience at least one episode in their lifetime.

What Causes Hives?

They typically are the result of an allergic reaction; however, there are many non-allergic causes. Finding the exact cause can be difficult.

Allergic reactions, certain foods, or medications are the common causes of hives.

What Are The Common Types Of Hives?

Acute: This type is usually the result of an allergic reaction and typically lasts only a few hours; some cases can come and go for up to six weeks.
- These skin rashes may appear within minutes to two hours after swallowing certain foods or medications, or applying certain products to the skin.
- An infection can also cause this type.
- People with this type of reaction often can easily identify and eliminate the cause.
Chronic: This type lasts more than six weeks. The cause is much more difficult to identify and may include medications, hidden infections or other internal problems.
- Your dermatologist will review your medical history. ask questions, and conduct a physical examination in order to try to identify the cause.
- Testing. such as allergy tests, blood work or a skin biopsy,. may be necessary.
Physical: This type of chronic hives is caused by one or more physical sources, such as sunlight, heat, cold, water, pressure, vibration, or exercise.
Sun (solar urticaria): form within minutes of sun exposure and typically fade within one to two hours after exposure.
Cold (cold urticaria): appear when the skin warms after exposure to cold or after prolonged chilling. These can cause wheezing, flushing, and fainting.
Pressure: can appear on parts of the body that have pressure on them for long periods of time. For example, the area at the top of the ankle where a sock band is tight.

Dermographism urticaria forms after stroking or scratching the skin, and can often occur with other forms of hives. This is the most common reason for chronic hives. These appear within a few minutes along the path of rubbing or scratching and last less than an hour.

What Foods Cause Hives?

In children, the most common foods are milk, eggs, and peanuts.
In adults, nuts, shellfish, and eggs are the common sources.
Fresh foods cause them more often than cooked foods.
Strawberries, food additives and preservatives are also known to be a trigger.

What Drugs Cause Hives?

Almost any prescription or over-the-counter medication can be a cause.
To help find the cause, it is important to tell your dermatologist about all prescriptions, over-the-counter medications or “natural" products you use.

What Type Of Infections Can Cause Hives?

Upper—respiratory tract infections and colds can trigger an outbreak, especially in children.
Viral, bacterial, and fungal infections can also cause them.

How Does A Dermatologist Treat Hives?

This type of rash usually disappears in a few hours or a day. An over-the-counter antihistamine can provide relief and reduce itchiness.There are many antihistamines available. You may have to try several types until you find the one that is most effective for you.

If you have hives that do not resolve within a week or do not respond to over-the-counter antihistamines. see your dermatologist. Your dermatologist may prescribe stronger antihistamines or combine an antihistamine with other medicines to control it. These other medications can include:

corticosteroids. which can provide relief but should only be used short-term
The immunosuppressant, cyclosporine; the anti-inflammatory drug. dapsone; or a type of antibacterial oral medication

There is also a new US. Food and Drug Administration-approved treatment for chronic idiopathic urticaria, which is caused by an autoimmune reaction. Talk with your dermatologist about whether this medication is right for you.

In severe, acute cases, an injection of epinephrine (adrenaline) may be necessary. Always seek immediate emergency medical treatment if you experience difficulty breathing.

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