Hives

Hives are itchy, raised bumps or welts that come and go on your skin. They’re most often red or skin-toned, but can look different depending on the color of your skin. They can be as small as a pencil eraser or as large as a dinner plate. Sometimes, you can also experience swelling deeper in your skin (angioedema).

Hives are common. They affect up to 20% of people, both kids and adults. In many cases, they’re harmless and short-lived. Sometimes, hives can become chronic. This means they last more than six weeks. These aren’t life-threatening, but they can be very bothersome and frustrating.

In rare cases, hives can be part of a severe allergic reaction or anaphylaxis. Call 911 or have someone take you to the emergency room if you’re having difficulty breathing, dizziness or swelling in your face, lips, tongue or throat.

Symptoms of hives

Hives are raised and welt-like. They’re usually itchy. It can be easy to confuse hives with other types of rashes. Common features of hives include:

• Itching (mild to severe)
• Last no more than 24 hours in one spot
• Can change size or shape
• Can move around different parts of your body
• Don’t leave a mark or bruise

Hives can appear on their own or with swelling under the skin of your lips, tongue, mouth or throat (angioedema).

Hives causes

Most of the time, healthcare providers can’t determine the cause of hives. They often happen seemingly at random and not due to a specific allergy. Possible triggers may include:

• Infections
• Emotional or physical stress
• Temperature (hot or cold)
• Vibrations, pressure or scratching your skin
• Exercise

Hives caused by an allergic reaction happen immediately after you’re exposed — for example, right after you eat a food you’re allergic to. In this case, you may also have other symptoms, like shortness of breath, vomiting or dizziness.

Anaphylaxis happens when you have a severe allergic reaction. Common anaphylaxis triggers include:

• Foods
• Medications
• Insect stings

Sometimes, hives can be a sign of ongoing medical conditions, like autoimmune diseases.

Risk factors

Healthcare providers don’t completely understand why hives happen. You may be more likely to get hives if you have allergies, asthma or eczema. The tendency to have more than one of these allergic conditions is called atopy.

Complications

Hives themselves are usually harmless. But severe allergic reactions that cause hives can be life-threatening. Anaphylaxis is a severe reaction that can cause dangerously low blood pressure and make it difficult to breathe. Get help right away if you have symptoms of anaphylaxis.

How doctors diagnose hives

A healthcare provider can diagnose hives by talking to you about your symptoms and looking at your skin. They might ask about things you may have touched or eaten, or other circumstances that could cause hives. In most cases, you won’t need a skin biopsy or blood tests. Your provider may refer you to an allergist or dermatologist if your hives are hard to manage.

Your provider may recommend allergy skin tests or blood tests if they think hives are part of an allergic reaction.

How are hives treated?

Hives aren’t permanent, but they can last a long time. Your healthcare provider might recommend treatments to make them less bothersome. Treatments could include:

• Antihistamines: This is usually the first step your provider will recommend. You may need higher doses of antihistamines than you’d usually take.
• Biologics: If you have chronic hives that aren’t managed with high doses of antihistamines, your provider might prescribe injectable medications. These include omalizumab (Xolair®) and dupilumab (Dupixent®).
• Remibrutinib (Rhapsido®): This is an oral medication that blocks cells from releasing histamine and other inflammatory chemicals that cause hives. Your provider may recommend it if high doses of antihistamines aren’t helping.
• Oral steroids: Sometimes, providers might prescribe oral corticosteroids to calm down severe hives. This is uncommon due to potential side effects.

If you’ve experienced anaphylaxis before, your provider will prescribe an epinephrine auto-injector to use if you have a severe reaction.

If you can determine what’s causing hives, you might be able to avoid triggers. This could include:

• Avoiding certain foods and medications, latex or insect stings
• Avoiding extreme changes in temperature
• Finding ways to manage stress that work for you
• Wearing loose-fitting, lightweight clothing

When should I see my healthcare provider?

Hives often get better without treatment. Call your healthcare provider if you have severe itching or hives that keep coming back.

Go to the emergency room or call 911 if you have signs of anaphylaxis, including:

• Wheezing or shortness of breath
• Swelling in your face, lips, tongue or throat
• Weakness, dizziness or other symptoms of low blood pressure
• Vomiting

How long does it take for hives to go away?

Hives usually go away on their own. Sometimes, they can last up to six weeks. Chronic hives can last months or years.