The first step in controlling hives is to identify the cause, if possible. If the source of the problem can be identified and avoided, try to avoid exposure to it in the future. A mild case of hives often disappears on its own after a few hours. A longer-lasting case should respond to the manufacturer's recommended dosage of an over-the-counter oral antihistamine. If your hives don't disappear in a few days, you should see a doctor. If you develop symptoms of angioedema or anaphylaxis, get medical help immediately.
For chronic or especially troublesome outbreaks of hives, your doctor will probably order a course of prescription antihistamines. Treatment with oral corticosteroids will sometimes reduce swelling when antihistamines don't work, but they are usually reserved for more severe cases. If you have the subsurface swelling of angioedema, you may require hospitalization.
If you are severely allergic to bee stings or other insect bites, certain foods, or medications, ask your doctor about prescribing an emergency kit containing epinephrine (also called adrenaline), which is an injection used to treat anaphylaxis and associated hives.
Call Your Doctor About Hives If:
Burning or itchy welts begin to develop in your throat; you may be at risk of suffocation. This requires immediate medical attention.
You develop hives accompanied by dry throat, cough, cold sweats, nausea, dizziness, difficult breathing, or a sharp drop in blood pressure after an exposure to a bee sting or insect bite or a new medication; this may be a severe allergic reaction known as anaphylaxis. This also requires immediate attention.
You experience recurring bouts of hives lasting a month or more; you may have a chronic condition that needs professional treatment.
You develop symptoms of angioedema, particularly in the head and neck; this requires immediate medical attention before the condition spreads to the throat or tongue and blocks the air passage to the lungs.
You develop hives after a blood transfusion; you may be having an allergic reaction to donor blood.