Symptoms of chronic hives include:

• Batches of welts, called weals, that can arise anywhere on the body.
• Welts that might be red, purple or skin-colored, depending on your skin color.
• Welts that vary in size, change shape, and appear and fade repeatedly.
• Itchiness, also called pruritus, which can be intense.
• Painful swelling, called angioedema, around the eyes, cheeks or lips.
• Flares triggered by heat, exercise or stress.
• Symptoms that persist for more than six weeks and recur often and anytime, sometimes for months or years.

When to see a doctor

See a healthcare professional if you have severe hives or hives that last for more than a few days.

Seek emergency medical care

Chronic hives do not put you at sudden risk of a serious allergic reaction, called anaphylaxis. If you get hives as part of a severe allergic reaction, seek emergency care. Symptoms of anaphylaxis include dizziness, trouble breathing, and swelling of the tongue, lips, mouth or throat.

The welts that come with hives are caused by the release of immune system chemicals, such as histamine, into your bloodstream. It's often not known why chronic hives happen or why short-term hives sometimes turn into a long-term problem.

The skin reaction may be triggered by:

• Heat or cold.
• Sunlight.
• Vibration, such as caused by jogging or using lawn mowers.
• Pressure on the skin, as from a tight waistband.
• Medical conditions, such as thyroid disease, infection, allergy and cancer.

In most cases, chronic hives is not predictable. In some people, the risk of chronic hives increases if they have certain medical conditions. These include infection, thyroid disease, allergy, cancer and swelling of the blood vessels, called vasculitis.

Chronic hives don't put you at sudden risk of a serious allergic reaction, called anaphylaxis. If you do get hives as part of a severe allergic reaction, seek emergency care. Symptoms of anaphylaxis include dizziness, trouble breathing, and swelling of the tongue, lips, mouth or throat.

To lower your likelihood of getting hives, use these self-care tips:

• Avoid known triggers. If you know what has triggered your hives, try to avoid that substance.
• Bathe and change your clothes. If pollen or animal contact has triggered your hives in the past, take a bath or shower and change your clothes if you're exposed to pollen or animals.

To diagnose chronic hives, your healthcare professional will likely talk with you about your symptoms and look at your skin. One of the telling features of chronic hives is that the welts come and go at random, with each spot usually lasting less than 24 hours. You might be asked to keep a diary to keep track of:

• Your activities.
• Any medicines, herbal remedies or supplements you take.
• What you eat and drink.
• Where hives appear and how long it takes a welt to fade and whether it leaves behind a bruise or other mark.
• Whether your hives come with painful swelling.

You also may need blood tests to determine the cause of your symptoms. An accurate diagnosis will guide your treatment. If needed to clarify the diagnosis, your healthcare professional might do a skin biopsy. A biopsy is a procedure to remove a sample of tissue for testing in a lab.

Treatment for chronic hives often starts with nonprescription anti-itch medicines, called antihistamines. If these don't help, your healthcare professional might suggest that you try one or more prescription-strength medicines. These include:

• Montelukast (Singulair).
• Doxepin (Silenor, Zonalon).
• Ranitidine.
• Omalizumab (Xolair).

For chronic hives that resist these treatments, your healthcare professional might prescribe a medicine that can calm an overactive immune system. Examples are cyclosporine (Neoral, Sandimmune), tacrolimus (Prograf, Protopic, others), hydroxychloroquine (Plaquenil) and mycophenolate (Cellcept).

Self-care

Chronic hives can go on for months and years. They can interfere with sleep, work and other activities. The following self-care tips may help you manage your condition:

• Avoid triggers. These can include foods, medicines, pollen, pet dander, latex and insect stings. If you think a medicine caused your welts, stop using it and contact your healthcare professional. Some studies suggest that stress or fatigue can trigger hives.

• Use a nonprescription anti-itch medicine. Nonprescription anti-itch medicine, called an antihistamine, that doesn't cause drowsiness may help ease itching. Examples include loratadine (Alavert, Claritin, others), famotidine (Pepcid AC), cimetidine (Tagamet HB), nizatidine (Axid AR) and cetirizine (Zyrtec Allergy). If your itching is worse when you're trying to sleep, you might try the type of antihistamine that causes drowsiness — diphenhydramine (Benadryl).

  Check with your healthcare professional before taking any of these medicines if you are pregnant or breastfeeding, have a long-term medical condition, or take other medicines.

• Apply cold. Soothe the skin by covering the itchy area with a cold washcloth or rubbing an ice cube over it for a few minutes.
• Take a comfortably cool shower or bath. Some people might relieve itching in the short term by taking a cool shower or bath. Try sprinkling the bath water with baking soda or oatmeal powder (Aveeno, others).
• Apply an anti-itch cream or lotion. Try a cream with menthol for a soothing effect.
• Wear loose, smooth-textured cotton clothing. Avoid wearing clothing that's rough, tight, scratchy or made from wool.
• Protect your skin from the sun. Liberally apply sunscreen about a half hour before going outdoors. When outdoors, seek shade to help relieve discomfort.
• Track your symptoms. Keep a diary of when and where hives occur, what you were doing, what you were eating, and so on. This may help you and your healthcare professional identify the thing that brings on symptoms for you.

You'll likely start by seeing your primary healthcare professional. Or you may be referred to an allergy specialist or a doctor who specializes in the diagnosis and treatment of skin conditions. This type of doctor is called a dermatologist.

What you can do

Here are some tips to help you get ready for your appointment.

• List your symptoms, when they occurred and how long they lasted.
• List any medicines you're taking, including vitamins, herbs and supplements. Even better, take the original bottles and a list of the doses and directions.
• List questions to ask your doctor.

For chronic hives, questions you may want to ask include:

• What is likely causing my symptoms?
• How long will hives last?
• What kinds of tests do I need? Do these tests require any special preparation?
• What treatments are available, and which do you suggest?
• What are the alternatives to the primary approach that you're suggesting?
• Do these treatments have any side effects?
• Do I need prescription medicine, or can I use nonprescription medicine to treat the condition?
• Does the medicine you're prescribing have a generic version?

What to expect from your doctor

Your healthcare professional is likely to ask you a few questions, such as:

• When did you first have symptoms?
• What did your skin reaction look like when it first appeared?
• Have your symptoms changed over time?
• Have you noticed anything that makes your symptoms worse or better?
• Do your hives mainly itch, or do they burn or sting?
• Do your skin lesions go away completely without leaving a bruise or a mark?
• Do you have any known allergies?
• Have you ever had a similar skin reaction before?
• Have you tried a new food for the first time, changed laundry products or adopted a new pet?
• What prescriptions, nonprescription medicines and supplements are you taking?
• Have you started taking any new medicines or started a new course of a medicine you've taken before?
• Has your overall health changed recently? Have you had any fevers, or have you lost weight?
• Has anyone else in your family ever had this kind of skin reaction? Do other family members have any known allergies?
• What at-home treatments have you used?