Hives are itching red welts or small bumps that last for 15 minutes to several hours. They usually appear suddenly and leave no trace when they disappear. Crops of hives may appear several times a day, they may even last for weeks, sometimes longer. Hives are harmless except when they cause throat swelling; this is rare but requires immediate treatment.
Hives can be caused by something taken internally, most often a medicine such as penicillin or aspirin.
Sometimes foods cause hives; shellfish and strawberries are well-known examples.
Hives are also sometimes caused by infection. Most of the time, we do not find the cause.
When treating hives, we try to find their cause. Medicine is prescribed to control the rash and itching.
Hives are usually controlled with antihistamines. (Caution: antihistamines may cause drowsiness; if you feel sleepy, don't drive. Also do not drink alcohol.)
Injections of epinephrine (Adrenalin) may be used for treating severe hives.
Sometimes epinephrine-like medicines taken by mouth are used in combination with antihistamines.
If these drugs don't stop hives, it's likely that cortisone will.
Hives usually improve within 24 hours of starting a medication.
Medicines applied to your skin such as lotions, creams, and sprays won't help your hives.
Cooling the skin often relieves severe itching. A cold shower is the simplest way.
Since heat worsens itching, avoid overheating and hot baths.