Hives

Overview

Hives (urticaria) are raised, usually itchy welts on the skin. When the body reacts to something, it releases histamine and other chemicals, which cause itching and swelling. Each welt usually fades within a day, but new ones can appear.

Hives can be an allergic reaction to a food, medicine, or insect sting. They also often follow a viral infection, especially in children. Many times, no cause is found. Hives that last more than 6 weeks are called chronic hives.

Symptoms

Hives can show up anywhere on the body.

• Raised, itchy welts or bumps
• Red or skin-colored welts that turn pale when pressed
• Welts that change shape, fade, and appear in new places

Less common

• Deeper swelling of the lips, eyelids, hands, or feet (angioedema)
• A burning or stinging feeling
• Rash that comes with exercise, heat, cold, or pressure

How it usually goes

• Minutes to hours: Welts appear, often soon after a trigger.
• Within a day: Each welt fades, though new ones can appear.
• Days to weeks: Most hives clear within a few days to weeks. Hives lasting more than 6 weeks are chronic.

When to get medical care

Causes

Hives happen when the body releases histamine into the skin. Triggers include foods like nuts, shellfish, eggs, and milk; medicines like antibiotics, aspirin, and ibuprofen; insect stings; infections, especially viral infections in children; and physical triggers like heat, cold, pressure, sun, and exercise.

In many people, especially with chronic hives, no cause is found.

Does it spread or run in families?

• It isn't contagious. You can't catch it from someone else.

Who is more likely to get it

• Allergies, including hay fever
• A recent infection
• Taking new medicines

Possible complications

• Angioedema: Deeper swelling of the lips, eyes, or throat
• Anaphylaxis: Severe allergic reaction; an emergency
• Chronic hives: Hives that last more than 6 weeks

Diagnosis

A healthcare professional can usually tell it's hives by looking at your skin. Finding the cause is often harder.

Questions you may be asked

• When the hives started and how long each welt lasts
• New foods, medicines, or supplements you've had
• Recent illness, insect stings, or contact with plants or animals
• Whether you have swelling of the lips, face, or throat, or trouble breathing
• Whether you've had hives before

The exam

They'll look at the welts and check for swelling, and may listen to your breathing.

Tests

Tests aren't usually needed for hives that go away quickly. Sometimes:

• Allergy testing: If a food, medicine, or sting may have caused a reaction.
• Blood tests: For hives that last more than 6 weeks, to look for other causes.

Treatment

Mild hives may not need treatment and often go away on their own. Antihistamines ease the itch.

Self-care

• Avoid what triggered the hives, if you know
• Take a non-drowsy antihistamine like cetirizine or loratadine
• Use cool compresses or a cool shower to ease itching
• Avoid hot baths and showers, and tight clothing that rubs the skin
• Try not to scratch

Medicines

Antihistamines block histamine, which causes the itching and swelling.

Medicine names link to drug information from the U.S. National Library of Medicine (MedlinePlus). OwieClear doesn't give doses: follow the label or your healthcare professional.

For hives that last weeks, your healthcare professional may suggest a higher dose of antihistamine, other prescription medicines, or a short course of steroids. People who've had severe reactions may need to carry epinephrine.

How it compares

Prevention

You can lower the chance of hives:

• Avoid foods, medicines, and other things that caused hives before
• Read ingredient labels carefully
• Wear a medical ID and carry epinephrine if you've had a severe reaction

Which doctor treats this

• Start with your primary care provider (family doctor or internist).
• They may send you to an allergist (allergy and asthma doctor).

Living with it

• Keep a simple diary of symptoms, triggers, and medicines to bring to visits.
• Bring a list of your medicines and questions to each visit.
• Use gentle, fragrance-free soaps and moisturizers.
• Protect your skin from the sun.
• Long-term illness can affect mood. Tell your doctor if you feel down or anxious.

Support groups and helplines

• Asthma and Allergy Foundation of America: Education and online support for asthma, allergies, and eczema.

Back to school, work, or sports

• Most people can keep working or going to school.
• Ask about changes that help, like extra breaks or a flexible schedule. Workers may be covered by the ADA. Students may get a 504 plan.

Children, pregnancy, and older adults

• Children: Hives are common in children, often after a viral infection. Call right away for any swelling of the face or trouble breathing.
• Pregnancy: Ask your healthcare professional which antihistamine is safe.
• Older adults: Drowsy antihistamines like diphenhydramine can cause confusion and falls; ask about non-drowsy choices.

Pregnancy and breastfeeding

• If you're pregnant or planning to be, tell your prenatal provider about this condition.
• Some skin medicines, like isotretinoin and retinoid creams, aren't safe in pregnancy.
• Don't start or stop any medicine on your own. Some are safe in pregnancy and some need to be changed.
• Ask before taking any pain reliever. The FDA advises avoiding ibuprofen and naproxen after 20 weeks unless your doctor says to.
• Breastfeeding: Most medicines are fine, but ask. The NIH LactMed database lists what's known about each one.

For caregivers

• Go to visits when you can and take notes.
• Keep a list of medicines, allergies, and doctors in one place.
• Learn the warning signs that need fast care.
• Take breaks and ask for help. Caregivers need care too.

Outlook

Most hives go away on their own within days to weeks. Chronic hives can last months but usually get better over time, and treatment helps control them.

Myths and facts

Getting ready for your visit

Photos and a list of possible triggers help the most.

What to bring

• Photos of the hives
• Foods, medicines, and supplements you took in the day before they started
• Recent illnesses or stings

Questions to ask

• What might be causing my hives?
• Should I be tested for allergies?
• Do I need to carry epinephrine?
• What should I take if they come back?

Research studies

Research studies test new ways to find and treat health problems. Some are looking for volunteers. Talk with your doctor before joining one.

Search ClinicalTrials.gov for studies on Hives