Hives — also called urticaria (ur-tih-KAR-e-uh) — is a skin reaction that causes itchy welts. Chronic hives are welts that last for more than six weeks and return often over months or years. Often, the cause of chronic hives isn't clear.
The welts often start as itchy patches that turn into swollen welts that vary in size. These welts appear and fade at random as the reaction runs its course.
Chronic hives can be very uncomfortable and interfere with sleep and daily activities. For many people, anti-itch medications (antihistamines) provide relief.
Symptoms of chronic hives include:
- Batches of welts (wheals) 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 (pruritus), which can be intense
- Painful swelling (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 your health care provider 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 (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
- Vibration, such as caused by jogging or using lawnmowers
- Pressure on the skin, as from a tight waistband
- Medical conditions, such as thyroid disease, infection, allergy and cancer
Chronic hives don't put you at sudden risk of a serious allergic reaction (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 experiencing hives or angioedema, take the following precautions:
- 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.