The Medical Meaning of Welts

"Welts" is a term for pink or red swollen bumps on the skin that are often itchy. Welts are usually an indication of either hives or angioedema, the swelling of the skin that can accompany hives.

This article covers what welts are, where they occur, how they feel, and how to treat them.

What Do Welts Mean, Medically?

"Welts" is a lay term for either hives or angioedema, which occurs when histamine, a chemical that is released during an allergic reaction, is released into the bloodstream. During this process, blood vessels pool together under the skin to cause welts.

Location and Appearance

Welts can appear anywhere on the body. They are usually red or pink with clear edges and have a white center. Their size can range from a pinpoint to about a centimeter (about the size of a ladybug) or larger. Sometimes hives can connect and spread across large areas of the body.

How Welts Feel (Sensation)

Hives usually have bumpy clear edges. Hives are usually itchy, and at times, they can sting or create a burning sensation.

Types and How Long They Last

Some hives last up to a week or longer. Acute hives last up to six weeks, while chronic hives last longer than six weeks.

Welts are usually one or both of the following:

• Hives: Officially known as urticaria, hives are welts of various sizes that are often itchy. Hives usually appear without warning, and they usually go away within a day, though some hives can last six weeks or longer. Hives can be caused by allergies, drug reactions, extreme heat or cold, sweating, stress, or pressure on the skin. Some hives have no clear cause.
• Angioedema can occur with or without the redness and itchiness of hives. Welts without hives can be caused by anti-inflammatory drugs (like aspirin and ibuprofen—Motrin or Advil), blood pressure medications, a blood disorder where there are not enough proteins to keep blood out of tissues, or a genetic blood disorder. Angioedema without hives usually requires testing from a doctor.

While hives are not usually dangerous, welts or hives around the throat that cause difficulty breathing or that appear suddenly and all over the body should get medical attention immediately.

Hives can be further labeled depending on how long they remain:

• Acute hives: These hives last for up to six weeks. They are usually spontaneous and occur because of a chemical reaction, a drug allergy, or a viral infection.
• Chronic hives: These welts can last longer than six weeks. Chronic hives can occur because of allergies, pollen, sweating, temperature changes, sunlight, or pressure on the skin. Some chronic hives can be the result of an autoimmune disorder, where the body's immune system attacks itself.
• Chronic idiopathic urticaria (CIU): These are chronic hives that last longer than six weeks but seem to have no known reason after testing or looking for triggers. CIU can last from one to five years.

Treatment at a Glance

If welts do not go away on their own, there are ways to treat them. Some nonmedical ways to heal from welts include:

• Wearing loose clothing
• Managing emotional stress
• Avoiding extreme heat or cold
• Staying dry, such as after exercising
• Avoiding hot showers
• Avoiding noted triggers, such as certain foods, chemicals, beauty products, plants, or weather conditions that cause hives

Medical treatments for welts include:

• Antihistamines, such as Benadryl (diphenhydramine) or Zyrtec (cetirizine): Antihistamines block the release of histamine, molecules that cells release when reacting to an allergy. These histamines are why red welts appear when the body breaks out into hives.
• Anti-itch cream
• Epinephrine, or adrenaline: In severe cases, such as swelling around the throat or a deadly allergic reaction, a healthcare professional might inject adrenaline.
• Steroids: Steroid shots are used for extreme cases of urticaria since they are quicker in reducing inflammation (the body's response to a foreign invader).
• For angioedema without hives, antihistamines might not be effective, and an examination by a healthcare provider is recommended. 

Summary

The term "welts" refers to hives, which are raised red or pink bumps created by the release of histamine in the blood. They are usually labeled hives or urticaria. Hives may include angioedema, which is swelling of the skin. Angioedema can appear with or without hives, which are usually itchy. Welts can appear anywhere on the body and usually disappear within a day. However, some can last longer.

Wearing loose clothing, avoiding triggers like food and environmental allergens, and avoiding extreme temperatures can help with treatment. Medical treatments for welts might include antihistamines, steroids, or, in extreme cases or life-threatening allergies, epinephrine, or adrenaline.

A Word From Verywell 

Hives can be frustrating to live with, especially if you don't know where they came from. The good news is that they tend to disappear on their own, usually within a day or week.

If you have a problem with repeated flare-ups of welts or hives, speak to a healthcare provider about possible triggers, or write down when they occur. It's possible that simple changes like avoiding heat, wearing comfortable clothing, and avoiding certain chemicals and plants could help you minimize flare-ups. The good news is that they are likely not dangerous and often disappear on their own.