What Is Urticaria?

"Urticaria" is the medical term for hives, which are red, itchy welts that can appear on the skin, sometimes accompanied by swelling. Hives can be caused by an allergic reaction, but some hives can appear without any known reason. Hives usually disappear in about a day, but some hives can remain for weeks and require analysis by a doctor.

This article covers the types of hives, their symptoms, how to treat hives, and how to prevent them from reappearing.

Types of Urticaria

Knowing the different types of hives is helpful for treatment. The type you have can indicate how long they will last and how they are treated.

Acute

"Acute urticaria" is the term for hives that appear suddenly and last no longer than six weeks.

Chronic

Chronic urticaria lasts for longer than six weeks and can appear suddenly or because of a known allergy. They can be very uncomfortable and interfere with sleep and daytime activities. Chronic urticaria should be tested by a healthcare provider, as it could be due to an autoimmune disease or an allergy.

Urticaria Symptoms

Urticaria can develop anywhere on the body. They can be 1 centimeter small or spread over large areas. Symptoms of hives include:

• Itching
• Redness
• Swelling under the skin, with clear edges (called angioedema) (Note: If swelling occurs around the throat or mouth, seek medical attention immediately.)
• Hives that grow or spread into larger areas
• Disappearing and reappearing swelling
• "Skin writing," or dermatographism (when hives result from pressure or scratches)

Urticaria Causes

Urticaria can appear without reason, but there are many known causes for them, including:

• Viral infection or illness
• Emotional stress
• Insect bites
• Animal dander
• Pollen
• Drug reactions
• Food allergies
• An autoimmune disorder
• Pressure or tight clothes
• Sweating
• Extreme heat or cold
• Sunlight
• Water

Diagnosis

Diagnosing urticaria can be as simple as looking at the hives. However, there are some ways to diagnose why they may have occurred, including:

• Observing if they occur with allergic reactions
• Observing how long the hives stay on the skin
• Performing a skin biopsy, in which a small amount of skin is removed and tested in a lab.
• Blood test

Treatment 

Hives can go away on their own. However, there are some ways to treat them, including:

• Antihistamines such as Benadryl (diphenhydramine) or Zyrtec (cetirizine): Antihistamines block the release of histamines, which are molecules that cells release when reacting to an allergy. Histamine release causes physical symptoms of allergy, like hives.
• Anti-itch cream: This is applied topically, over the hives.
• Epinephrine, or adrenaline: In severe cases, such as swelling around the throat, a healthcare professional might inject a shot of adrenaline.
• Steroids: Steroids are also used for extreme cases of urticaria since they quickly reduce inflammation (the body's response to a foreign invader).

Prevention

One way to prevent hives from reappearing is to monitor flare-ups and note triggers to avoid in the future. This includes certain foods, plants, and chemicals (like additives in foods). Cold or hot temperatures should also be avoided.

Other tips for urticaria prevention are:

• Wearing loose-fitting clothing
• Avoiding hot showers
• Moisturizing daily with a fragrance-free moisturizer
• Avoiding stress
• Managing allergies
• Following a medication regimen if recommended by a doctor
  

Summary

"Urticaria" is the medical term for hives. Acute hives last for up to six weeks, while chronic hives last longer. Symptoms of hives include redness, swelling, itching, and spreading across the skin. Hives can develop without reason, but they also can be due to allergies, an autoimmune disorder, emotional stress, extreme heat or cold, or reactions to medication.

Treatments for hives include antihistamines like Benadryl, anti-itch creams, and an adrenaline shot or steroids in extreme cases, such as when swelling appears around the throat. Hives can be prevented by avoiding allergens or other triggers, avoiding stress, wearing loose clothing, moisturizing with a fragrance-free product, and taking medication as prescribed.

A Word From Verywell

Hives can happen to anyone. They are likely to disappear within a day, but if your hives last a long time or feel very uncomfortable, see a healthcare provider. A provider can evaluate the cause of your hives and prescribe medication if nonprescription remedies aren't helping. Hives are manageable, and, with treatment and understanding your triggers, they can be avoided.