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Hives (urticaria) that cause difficulty breathing or swallowing require emergency medical attention. Mild cases of acute hives may not require treatment. They often appear suddenly and subside without treatment within days or even minutes. Wheals (individual hives) that appear suddenly in children before disappearing quickly without recurring usually indicate the presence of a viral infection. For this reason, parents of children with this type of hives should consult a physician.

When treatment is necessary, the best method is to find and address the underlying cause. If a specific food is suspected, it should not be ingested. Keeping a food diary and closely reading food packaging labels can help identify the substance(s) that cause hives.

Other treatment and prevention methods will depend on the source of the reactions. For instance, in the case of solar urticaria, sunscreen and general sun protection are recommended. Some sufferers need sunscreens with zinc oxide or titanium dioxide to completely block the sun’s rays. Those with cold urticaria can prevent hives by avoiding exposure to cold air as much as possible, and wearing warm clothing when exposure occurs. Individuals with cold urticaria should also avoid swimming in non-heated water. This can trigger enough vasodilation (widening of the blood vessels) to significantly drop blood pressure and lead to drowning.

Vigorous drying with a towel after a bath should be avoided as well as the use of harsh soaps and frequent bathing. This helps to reduce dry skin in those people susceptible to hives, particularly those with dermatographism (hives caused by friction between clothes and the skin). Wearing loose, comfortable clothing can also benefit those who suffer from pressure urticaria, as tight clothing can trigger a new outbreak.

Other treatment options include:

• Applying calamine lotion to affected areas.
  
• Avoiding activities that cause sweating.
  
• Staying calm. Stress may worsen the itching.
  
• Taking cool baths or applying cold compresses to reduce swelling and discomfort. Hot baths and showers should be avoided because these can trigger a recurrence.

In addition, patients with hives should not drink alcohol and should avoid scratching their skin. These activities can worsen itching in some cases.

After an episode of allergic urticaria, medications called antihistamines may be recommended to relieve symptoms. Antihistamines block the release of histamines into the body, which occurs as the result of an allergic reaction. Older antihistamines used to cause drowsiness but there are newer ones on the market that cause little or no drowsiness. Physicians may prescribe a combination of two or three antihistamines for the treatment of hives.

Specific drugs that have proven success in treating hives are:

• Short-acting H1 antihistamines. The primary medications for mild cases of hives. They are available over-the-counter and are inexpensive. However, they may cause drowsiness.
  
  
• Long-acting H1 antihistamines. These are available only by prescription and are more expensive. However, they usually do not cause sleepiness and need to be taken less frequently.
  
  
• Corticosteroids. Drugs that suppress the allergic response of the immune system. They relieve the inflammation and swelling symptoms and lessen the chance of the eruption recurring. Corticosteroids may be prescribed for severe cases of hives when antihistamines fail to relieve symptoms. They are typically used on a short-term basis, due to the risk for side effects. Antihistamines are then used to maintain the results.
  
  
• Epinephrine. An emergency treatment measure used for anaphylactic shock and most other severe allergic reactions that may include hives. This drug is usually administered via an injection. Patients at high risk for severe attacks may be advised to always carry epinephrine with them and learn how to self-administer the medication. Epinephrine injections may also be administered in an emergency room setting.
  
  
• Antidepressants. Tricyclic antidepressants (e.g., doxepin) are also a potent antihistamine that may help relieve chronic hives. These drugs may cause a sedative effect in some patients and may have other side effects, such as blurred vision, urine retention and dry mouth.

Low doses of cyclosporine, an immunosuppressant often used to treat psoriasis or to weaken the immune system in organ transplant recipients, may be used to treat severe cases of hives. However, the drug causes considerable side effects when taken for a long period of time.

Other non-standard therapies that may be used in combination with antihistamines to treat stubborn cases of hives include antiinflammatory antibiotics, blood pressure drugs, asthma drugs and gout medications.  

In addition, a number of medications are currently being studied for potential use in the treatment of hives. These include:

• H1 and H2 blocking drugs. Medications not yet approved by the U.S. Food and Drug Administration (FDA) for treating hives. Studies have found these medications effective in patients who do not respond to H1 or H2 type antihistamines.
  
  
• H2 antihistamines. These medications have been found to reduce the redness and swelling when given in conjunction with H1 antihistamines. They were originally developed to treat ulcers and have not yet been approved by the FDA for the treatment of hives.
  
  
• Antimalarials. In a recent study, 83 percent of participants experienced an improvement or a complete clearing of their chronic idiopathic hives after taking an antimalarial (a drug used to treat malaria) for three months or more.

It is important to note that patients with hives that persist despite treatment should consult their physician.