What causes hives?
The three most common causes are infection, foods and medications/herbs.  The most common medicines causing hives are penicillin and aspirin.  Common foods that cause hives are shellfish and strawberries.  The most common infection causing hives is mononucleosis.  Occasionally physical agents, such as pressure or cold, can cause hives.  Most often, the cause of hives is not found.  Fortunately, hives can be treated successfully without knowing the cause.

Treatment
In treating your hives, we try to find their cause.  Medicine is prescribed to control the rash and itching.

Since medicines are the most common cause of hives, please list all the medicines you’ve been taking – including headache tablets, allergy pills, medicines for stomach discomfort, laxatives, tranquilizers, cough medicines, and painkillers.  Think for a minute of what your medicine cabinet contains.  List any unusual food you ate in the two days before the hives first appeared.  Have you had any recent illnesses?

Answers to these questions may help find the cause of your hives.  Meanwhile, you’ll be given medicines to control them.

Hives are usually controlled with antihistamines.  Often one type of antihistamine is prescribed for daytime use, and a different antihistamine for bedtime.  Don’t combine different antihistamines unless approved by your health care provider.

CAUTION:  Antihistamines sometimes cause drowsiness; if you feel sleepy, don’t drive.  Don’t drink alcoholic beverages when taking antihistamines.

Injections of epinephrine (Adrenaline®) may be used for treatment of 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 with medicines in 24 hours or less.  If you are not feeling better within 24 hours, contact a health care provider.

Medicines applied to your skin – lotions, creams, sprays, and so on – won’t help your hives.  However, cooling the skin often relieves severe itching.  A cold shower is the simplest way.  If your hives are confined to a small area, an ice pack is useful.  Since warmth worsens itching, avoid overheating and hot baths.

When your hives have cleared up, keep taking the medicines in the same way for two or more days.  Once you’ve been free of hives for two days, gradually take less and less of your medicines over the next seven or eight days.  If hives come back while you’re tapering off the medicines, resume the original amount until the hives disappear.  It’s a good idea to take medicines for about 10 days after the hives have cleared up while your body eliminates their cause.