Urticaria (Chronic Hives)
Hives, also known as urticaria, are batches of raised, red or white itchy welts (wheals) of various sizes that appear and disappear. While most cases of hives go away within a few weeks or less, for some people they are a long-term problem. Chronic hives are defined as hives that last for more than six weeks or hives that go away but recur frequently.
In most cases of chronic hives, a cause is never clearly identified. In some cases, the condition may be related to an underlying autoimmune disorder — when your body becomes allergic to itself. Chronic hives can also be linked to other health problems such as thyroid disease or lupus.
While the underlying cause of chronic hives is usually not identified, treatment can help with symptoms. For many people, a combination of antihistamine medications provides the best relief.
Chronic hives are an inflammation of the skin triggered when certain cells (mast cells) release histamine and other chemicals into your bloodstream, causing small blood vessels to leak. The exact cause of chronic hives isn't well understood — and triggers can be difficult to pinpoint. Chronic hives are thought to be caused by an immune system (autoimmune) disorder and may be linked to another health problem such as thyroid disease or a blood disorder.
Rarely, a reaction to medication, food, insects, parasites or infection is identified as an underlying cause. But in 80 percent to 90 percent of cases, the cause of chronic hives is never identified even after testing and monitoring symptoms. While heat, nonsteroidal anti-inflammatory medications or other stimuli may worsen chronic hives, signs and symptoms may come and go with no apparent trigger.
You may be at greater risk of chronic hives if you:
When to seek medical advice:
- Are a woman — chronic hives occur twice as often in women as they do in men
- Are an older adult
- Have had hives or angioedema before
- Have had other allergic reactions
- Have a disorder associated with hives and angioedema, such as lupus, lymphoma or thyroid disease
- Have a family history of hives, angioedema or hereditary angioedema
While chronic hives and angioedema usually aren't life-threatening, they can be debilitating — and in some cases are a sign of an underlying health problem. See your doctor if you have severe hives, hives that don't respond to treatment or hives that continue to appear for more than a couple of days.
Seek emergency care if you feel lightheaded, have difficulty breathing or if you feel your throat is swelling.
Hives appear as small round wheals, rings or large patches and may change shape. They usually itch and may be surrounded by a red flare. Hives tend to occur in batches.
Individual hives can last from four to 36 hours. As each hive disappears, other new hives may develop.
About 40 percent of people with chronic hives also have
angioedema. Signs and symptoms of angioedema include large welts or swelling of the skin that may occur around the eyes and lips, hands, feet, genitalia and inside the throat. Swelling in the throat can obstruct breathing and requires emergency treatment.
Symptoms may not occur all the time. They may come and go with no apparent trigger. For some people certain conditions such as heat, exertion or stress can make symptoms worse.
Your doctor will ask you a number of questions and do a physical exam. Your doctor may ask you to keep a diary for several weeks. You may need to keep track of:
While it isn't always possible to determine the underlying cause of chronic hives, your doctor will want to learn as much as possible about what might be causing your symptoms. Depending on your symptoms and medical history, your doctor may order one or more tests, including:
- All activities
- Any medications or herbal supplements you take
- What you eat and drink
- Where hives appear and how long individual hives last
- Blood tests. Your doctor may ask for blood tests to check for levels and function of specific blood cells and proteins.
- Allergy tests. Your doctor may use skin or blood tests to see whether your hives may be caused by an allergic reaction, especially if the hives seem related to specific triggers.
- Tests to rule out underlying conditions. You may need additional tests to make certain your hives are not caused by an underlying health condition such as hepatitis or thyroid disease.
Hives and angioedema can cause itching and discomfort. In more serious cases — when swelling occurs inside your mouth or throat — complications can include difficulty breathing leading to a loss of consciousness. If you have a swollen throat, seek medical care immediately.
Anaphylactic shock (anaphylaxis) is a serious allergic reaction involving your heart or lungs. Your bronchial tubes narrow, it's difficult to breathe, and your blood pressure drops causing dizziness and perhaps loss of consciousness or even death. Anaphylactic shock occurs rapidly, and requires immediate medical care.
Finding an effective treatment for chronic hives can be challenging. In cases where a trigger is identified — such as a reaction to a certain food, medication or physical stimulus — treatment includes avoiding the trigger. If your chronic hives are caused by an underlying health condition, they may improve when the underlying condition is treated.
Symptoms can be treated effectively in most people with over-the-counter or prescription medications. Work with your doctor to find the medication — or combination of medications — that works best for you. If the first medication you try doesn't relieve your symptoms, talk to your doctor about trying something else.
These medications block the symptom-producing release of histamine, controlling symptoms for the majority of people with chronic hives — but they do not treat the underlying cause of the rash. You may need to take antihistamines every day or only as needed for a flare-up. Some of these medications are available over-the-counter, while others require a prescription. A combination of antihistamines may work best.
Your doctor may have you start with newer, nonsedating or low-sedating antihistamines, such as:
Some of these medications may not be suitable if you are pregnant, have heart disease or are taking other medications such as the antibiotic erythromycin or the antifungal medication ketoconazole.
- Loratadine (Claritin)
- Fexofenadine (Allegra)
- Cetirizine (Zyrtec)
If a nonsedating antihistamine doesn't work, your doctor may recommend taking a different type of antihistamine. These antihistamines, which can make you drowsy, include:
- Hydroxyzine (Atarax, Vistaril)
- Diphenhydramine (Benadryl, others)
If antihistamines alone don't relieve your symptoms, other possible treatments include:
Other medications are still being studied to determine whether they may be useful for treating chronic hives. These include:
- Oral corticosteroids. Oral corticosteroids such as prednisone can help lessen swelling, redness and itching — but are only used short term for severe hives or angioedema because they can cause serious side effects.
- Tricyclic antidepressants. Examples include amitriptyline, nortriptyline and doxepin. These medications have antihistamine properties and can help relieve itching.
- Epinephrine. For a severe attack of hives or angioedema, you may need an emergency injection of adrenaline (epinephrine) and a trip to the emergency room. If you have repeated attacks, despite treatment, your doctor may prescribe — and instruct you how to use — adrenaline (EpiPen) to carry with you for use in emergency situations.
- Leukotriene receptor antagonists. Montelukast is the only medication of this type currently available in the United States. This type of medication may be helpful when used along with antihistamines.
- Cyclosporine. This immune system suppressant can help with symptoms, but it can cause serious side effects and needs to be monitored carefully.
The following precautions may help prevent hives and angioedema:
- Avoid known triggers. These may include certain foods or food additives, medications or situations such as temperature extremes or emotional stress.
- Keep a diary. Track all of your activities, when and where hives occur, and what you eat. This may help you and your doctor identify triggers.
- Avoid medications that may trigger hives. These include aspirin, codeine and any medications your doctor told you not to take.
- Avoid alcohol. It causes blood vessels to expand and can worsen symptoms. In some people alcohol triggers urticaria.