Chronic hives (urticaria)

Chronic hives (urticaria)

Definition  :

Chronic 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 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, chronic hives may be related to an underlying autoimmune disorder, 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, antihistamine medications provide the best relief.

Symptoms:

Hives generally:

• Appear as small round wheals, rings or large patches and may change shape
• Itch and may be surrounded by a red flare
• Occur in batches, and often appear on the face or the extremities

Individual hives can last from 30 minutes to 36 hours. As some hives disappear, 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. Angioedema may itch less than hives do, but can cause pain or burning.
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.

When to see a doctor
Although 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
• Hives that continue to appear for several days

Seek emergency care if you:

• Feel lightheaded
• Have difficulty breathing
• Feel your throat is swelling

Causes:

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 lupus.

Rarely, a reaction to medication, food, food additives, insects, parasites or infection is identified as an underlying cause of chronic hives. But in most cases, the cause of chronic hives is never identified, even after testing and monitoring symptoms. Heat, cold, pressure, sunlight or other environmental stimuli may worsen chronic hives. Certain pain medications, such as aspirin, ibuprofen (Advil, Motrin, others) and naproxen sodium (Aleve, Anaprox, others), also can worsen chronic hives.

Complications:

Complications of hives and angioedema may include:

• Itching. Hives and angioedema can cause itching and discomfort.
• Difficulty breathing. 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.
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• Anaphylactic shock (anaphylaxis). This is a serious allergic reaction involving your heart or lungs that can also be associated with hives and angioedema. 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.

Treatments and drugs:

Finding an effective treatment for chronic hives can be challenging. In cases in which 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.

Oral antihistamines
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. Antihistamines are divided into two categories — older, first-generation drugs and newer, second-generation medications. Each category includes nonprescription and prescription drugs. A combination of antihistamines may work best.

Second-generation, newer antihistamines. Your doctor may have you start with newer, nonsedating or low-sedating antihistamines because they are generally as effective and better tolerated than first-generation antihistamines. Examples include:

• Loratadine (Claritin, Alavert)
• Fexofenadine (Allegra)
• Cetirizine (Zyrtec)
• Levocetirizine (Xyzal)
• Desloratadine (Clarinex)

First-generation, older antihistamines. If a nonsedating antihistamine doesn't work, your doctor may recommend taking a first-generation antihistamine. These antihistamines can make you drowsy and impair your ability to drive or perform other tasks that require physical coordination. For that reason, your doctor may recommend that you take this type of antihistamine before bedtime and switch to a second-generation drug during the daytime. This class of antihistamines includes:

• Hydroxyzine (Vistaril)
• Diphenhydramine (Benadryl)
• Chlorpheniramine (Chlor-Trimeton)

Check with your doctor before taking any of these medications if you're pregnant or breast-feeding, have a chronic medical condition, or are taking any other medications.

Other medications
If antihistamines alone don't relieve your symptoms, other possible treatments include:

• H-2 antagonists. These medications, such as cimetidine (Tagamet), ranitidine (Zantac), nizatidine (Axid) and famotidine (Pepcid AC), can be used along with antihistamines. Some common side effects from this class of medications range from gastrointestinal problems to headache.
  
• Oral corticosteroids. Oral corticosteroids, such as prednisone, can help lessen swelling, redness and itching — but are usually used only a short term for severe hives or angioedema because they can cause serious side effects. Topical corticosteroids usually aren't effective for chronic hives. Corticosteroids can weaken your immune system, making it easier for you to get an infection or worsening an existing infection you already have.
  
• Tricyclic antidepressants. The tricyclic antidepressant doxepin (Zonalon) has antihistamine properties and can help relieve itching. Doxepin may cause dizziness or drowsiness.

Other medications are still being studied to determine whether they may be useful for treating chronic hives. These include:

• Leukotriene modifiers. Montelukast (Singulair) and zafirlukast (Accolate) are asthma medications that may be helpful when used along with antihistamines. Side effects of these drugs may include behavior and mood changes.
  
• Cyclosporine. This immune system suppressant can help with symptoms, but it can cause serious side effects and needs to be monitored carefully. The Food and Drug Administration warns that taking cyclosporine (Gengraf, Neoral, others) puts you at greater risk of opportunistic infections, such as the activation of a previous infection.
  
• Omalizumab (Xolair). This medication is normally given by injection to treat allergic asthma. It may help people who have chronic hives caused by an autoimmune response that haven't been helped by antihistamines. Only very small studies have been completed, so more clinical trials are needed.