Hives are pink or red bumps on the skin. These bumps are also known as wheals. The bumps can itch, burn, or sting. Hives can occur anywhere on the body. They vary in size and shape and can form in clusters. Individual hives can appear and go away quickly. New hives may develop as old ones fade. Hives are common and usually harmless. Occasionally hives are a sign of a serious allergy.
Hives are often caused by an allergic reaction. It may be an allergic reaction to foods such as fruit, shellfish, chocolate, nuts, or tomatoes. It may be a reaction to pollens, animal fur, or mold spores. Medicines, chemicals, and insect bites can also cause hives. And hives can be caused by hot sun or cold air. The cause of hives can be difficult to find.
You may be given medicines to relieve swelling and itching. Follow all instructions when using these medicines. The hives will usually fade in a few days, but can last up to 2 weeks.
Follow these tips:
Try to find the cause of the hives and eliminate it. Discuss possible causes with your healthcare provider. Future reactions to the same allergen may be worse.
Don’t scratch the hives. Scratching will delay healing. To reduce itching, apply cool, wet compresses to the skin.
Dress in soft, loose cotton clothing.
Don’t bathe in hot water. This can make the itching worse.
Apply an ice pack or cool pack wrapped in a thin towel to your skin. This will help reduce redness and itching. But if your hives were caused by exposure to cold, then do not apply more cold to them.
You may use over-the counter antihistamines to reduce itching. Some older antihistamines, such as diphenhydramine and chlorpheniramine, are inexpensive. But they need to be taken often and may make you sleepy. They are best used at bedtime. Don’t use diphenhydramine if you have glaucoma or have trouble urinating because of an enlarged prostate. Newer antihistamines, such as loratadine, cetirizine, and fexofenadine, are generally more expensive. But they tend to have fewer side effects, such as drowsiness. They can be taken less often.
Another type of antihistamine is used to treat heartburn. This type includes ranitidine, nizatidine, famotidine, and cimetidine. These are sometimes used along with the above antihistamines if a single medicine is not working.
Follow up with your healthcare provider if your symptoms don't get better in 2 days. Ask your provider about allergy testing if you have had a severe reaction, or have had several episodes of hives. He or she can use the allergy testing to find out what you are allergic to.
Call your healthcare provider right away if any of these occur:
Fever of 100.4°F (38.0°C) or higher, or as directed by your healthcare provider
Redness, swelling, or pain
Foul-smelling fluid coming from the rash
Call 911 if any of the following occur:
Swelling of the face, throat, or tongue
Trouble breathing or swallowing
Dizziness, weakness, or fainting