Hives on light skin
Hives may be accompanied by angioedema, which causes red, swollen welts.
Hives on dark skin
Hives, also known as urticaria, are reddened, itchy welts that may be triggered by exposure to certain foods, medications or other substances.
Hives (urticaria) are red, itchy welts that result from a skin reaction. The welts vary in size and appear and fade repeatedly as the reaction runs its course.
The condition is considered chronic hives if the welts appear for more than six weeks and recur frequently over months or years. Often, the cause of chronic hives is not clear.
Chronic hives can be very uncomfortable and interfere with sleep and daily activities. For many people, antihistamines and anti-itch medications provide relief.
Angioedema may cause large welts below the surface of the skin, particularly on the eyes and lips. Angioedema may also affect the hands, feet and throat.
Signs and symptoms of chronic hives include:
- Batches of red or skin-colored welts (wheals), which can appear anywhere on the body
- Welts that vary in size, change shape, and appear and fade repeatedly as the reaction runs its course
- Itching, which may be severe
- Painful swelling (angioedema) of the lips, eyelids and inside the throat
- A tendency for signs and symptoms to flare with triggers such as heat, exercise and stress
- A tendency for signs and symptoms to persist for more than six weeks and to recur frequently and unpredictably, sometimes for months or years
Short-term (acute) hives appear suddenly and clear up within a few weeks.
When to see a doctor
See your doctor if you have severe hives or hives that continue to appear for several days.
Seek emergency medical care
Chronic hives don't put you at any sudden risk of a serious allergic reaction (anaphylaxis). If you do experience hives as part of a serious allergic reaction, seek emergency care. Signs and symptoms of anaphylaxis include dizziness, trouble breathing, and swelling of your lips, eyelids and tongue.
The welts that come with hives arise when certain cells release histamine and other chemicals into your bloodstream.
Doctors often can't identify the reason for chronic hives or why acute hives sometimes turn into a long-term problem. The skin reaction may be triggered by:
- Pain medications
- Insects or parasites
- Heat or cold
- Alcohol or food
- Pressure on the skin, as from a tight waistband
In some cases, chronic hives may be related to an underlying illness, such as a thyroid disease or, rarely, cancer.
Chronic hives don't put you at any sudden risk of a serious allergic reaction (anaphylaxis). But if you do experience hives as part of a serious allergic reaction, seek emergency care. Signs and symptoms of anaphylaxis include dizziness, trouble breathing, and swelling of your lips, eyelids and tongue.