A Guide to Hives

Medically Reviewed By Joan Paul, MD, MPH, DTMH

Hives are swollen, itchy, or discolored bumps, usually resulting from an allergic reaction or immune system response. They are often mild and improve on their own quickly, but some cases can be chronic. Hives can range from mild and temporary to severe and chronic.

Treatment isn’t always necessary for mild cases. Still, topical ointments, medications, and avoiding triggers can help alleviate symptoms and help with recovery.

This article explains hives, including their symptoms, causes, and triggers. It also details diagnosis, treatment, outlook, and when to contact a health professional.

Types

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Milles Studio/Stocksy United

There are two primary types of hives:

  • Acute urticaria or hives: These last a short time — from a few minutes to 6 weeks. They are a reaction to an irritant or allergens, such as pollen or certain foods.
  • Chronic urticaria or hives: This condition is when you have hives for 6 weeks Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source or longer. The cause is often unknown, but allergic reactions are sometimes responsible. The two subtypes are:
    • chronic spontaneous urticaria occur without a known trigger.
    • chronic inducible urticaria develop as a response to a known trigger.

Causes

Hives are often the result of an immune system response or an allergic reaction. People with allergies may be more likely to develop hives than people without.

When the immune system detects an irritant, allergen, or foreign particle, it produces the Immunoglobulin E (IgE) antibody.

IgE antibodies cause cells to release histamine to disable or kill the irritant. Inflammation from histamine often produces hives.

Not everyone experiences the same reaction or has the same allergies. Some people have a hypersensitive response — the immune system overreacts to an irritant.

Also, chronic hives may be the result of autoimmune conditions and infections, according to a 2023 review Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source . Still, it’s not clear why some cases of hives are chronic.

Triggers

Many substances can trigger hives, including:

  • viral infections, such as a common cold or hepatitis
  • some medical treatments, such as radiotherapy or blood transfusions
  • exercise
  • physical stimuli or irritation, such as from:
    • pressure or constriction, such as from clothing or bearing weight
    • cold or heat
    • changes in temperature
    • sun exposure
    • smoke exposure

Allergens may also trigger hives, such as:

  • insect bites or stings, such as dust mites
  • latex
  • animal dander or fur
  • plants
  • pollen
  • molds and spores
  • some medications, for example, antibiotics, aspirin, and ibuprofen
  • some foods, such as:
    • peanuts and other nuts
    • eggs
    • shellfish

A 2019 review Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source also suggests that the following factors may possibly worsen hives:

  • stress
  • sleep disturbances
  • infection
  • irregular use of antihistamines

The allergen or trigger can vary per person. Not everyone with hives has the same triggers, and not everyone who experiences triggers will develop hives. Sometimes, the cause or trigger of hives is unknown.

Symptoms

Hives usually appear as small bumps or welts on the skin that:

  • are your skin color or appear discolored
  • are swollen
  • appear raised from the skin
  • feel itchy
  • cause a burning sensation

Hives can also appear as more extensive areas of swelling. Sometimes, hives develop alongside angioedema, swelling that develops suddenly. It commonly occurs on the face, hands or feet, or genitals.

Hives can develop anywhere on the skin, including the mucus membranes. These moist tissues line your eyes, mouth, and other areas, such as the genitals.

Often, hives go away within a few hours Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source to 1 day and do not leave a mark.

When to see a doctor

Contact your doctor if:

  • You experience hives that last for more than a few days or go away and come back.
  • Your symptoms cover a large area of the body.
  • You experience symptoms after exposure to one of your known allergens.
  • You have symptoms that feel severe or concerning.
  • You have already been prescribed treatment, but it’s not working.
  • You have:
    • an open wound or broken skin that leaks fluid or pus

In rare cases, a severe allergic reaction, known as anaphylaxis, can cause hives. Some severe symptoms of infection and swelling are also medical emergencies.

Learn more about symptoms and first aid for anaphylaxis.

Call 911 for any of the following symptoms alongside skin symptoms:

Talk with your doctor if you are unsure about whether your skin condition requires care.

Diagnosis

A healthcare professional will ask about your symptoms and medical history and examine your skin to reach a diagnosis. If you have hives that go away and come back, consider keeping a photo to show the doctor.

Your doctor may also ask about:

  • your medications and supplements
  •  how long have you had hives, and when do they appear
  • whether you have any other symptoms

Healthcare professionals can often diagnose hives based on their appearance and your medical history, but they may also recommend Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source tests to rule out other possible causes or identify allergies.

Treatment and home care

Treatment for hives can depend on the severity and underlying cause.

For example, mild acute hives may improve on their own within a few hours or days.

If you need treatment, options include:

  • topical anti-itch ointments or lotions, such as ointments containing menthol
  • over-the-counter (OTC) antihistamines, medications to help reduce swelling and itching
  • prescription medications, such as prescription antihistamines

Some of these products are available OTC or by prescription. Be sure to ask a doctor or pharmacist about which may be the most safe and effective for you.

One essential treatment approach is reducing your exposure to triggers and other irritation. For example, if you experience hives after eating a specific food item, you need to avoid it.

If you are unsure of your triggers, consider keeping a symptom diary. Record when you experience hives and what you did or ate beforehand.

This may help you spot trends and identify triggers. You can also talk with your doctor about triggers and advice for avoiding exposure.

Learn more about home remedies and self-care for hives.

Treatment for chronic or severe hives can include:

  • antihistamines
  • injected medications, such as omalizumab (Xolair)
  • corticosteroid medications
  • light therapy or phototherapy, which uses light to ease inflammation

If you have allergies, your medical team may prescribe an auto-injector (EpiPen, Emerade, Autoject). This can provide emergency relief if you experience a severe allergic reaction.

Read more about treatment options for allergies.

Outlook

Many cases of hives improve on their own, leaving no trace or marks on the skin. With acute hives, this may happen as quickly as a few minutes, but some people may experience them for days or weeks.

If you experience a severe allergic reaction, call 911 or your local medical emergency service.

Chronic hives last 6 weeks or longer. Still, the 2023 review Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source suggests that chronic hives may also go away on their own. Reviewers say this may take about 3–5 years.

In some cases, hives may go away and then come back.

In the meantime, treatment can help speed recovery, alleviate irritating symptoms, and improve quality of life.

Talk with your doctor about treatment and outlook.

Summary

Hives are swollen, itchy, or discolored bumps that appear on the skin. They develop due to irritants, allergens, and other triggers that cause an immune reaction and inflammation.

Many cases of hives are mild and improve on their own. Still, some cases can be chronic and last for weeks or years. Treatment with topical ointments and oral medication may help the skin recover and alleviate discomfort.

Sometimes hives occur as a symptom of a severe allergic reaction. Call 911 or your local emergency service for concerning symptoms alongside hives, such as difficulty breathing, severe or widespread swelling, and confusion.

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Medical Reviewer: Joan Paul, MD, MPH, DTMH
Last Review Date: 2023 Jul 26
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.