Hives
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.
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 respont 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
-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 respont 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
Hives and angioedema are caused by triggers that produce a skin or tissue reaction by stimulating certain cells (mast cells) to release histamine and other chemicals into your bloodstream. Sometimes it's not possible to pinpoint the cause of hives and angioedema, especially when these conditions become chronic or recur.
Allergic reactions are one common trigger of acute hives and angioedema. Common allergens include:
Additional triggers include:
Hives and angioedema also occasionally occur in response to blood transfusions, immune system disorders such as lupus, some types of cancer such as lymphoma, certain thyroid conditions, and infections with bacteria or viruses such as hepatitis, HIV, cytomegalovirus or Epstein-Barr virus.
Hereditary angioedema is a rare inherited (genetic) form of the condition. It's related to low levels or abnormal functioning of certain blood proteins (C1 inhibitors) that play a role in regulating how your immune system functions.
Allergic reactions are one common trigger of acute hives and angioedema. Common allergens include:
- Foods. Many foods can trigger reactions in people with sensitivities. Shellfish, fish, peanuts, tree nuts, eggs and milk are frequent offenders.
- Medications. Almost any medication may cause hives or angioedema. Common culprits include penicillin, aspirin, ibuprofen (Advil, Motrin, others), naproxen (Aleve, others) and blood pressure medications.
- Other allergens. Other substances that can cause hives and angioedema include pollen, animal dander, latex and insect stings.
Additional triggers include:
- Environmental factors. In some people, environmental factors can stimulate release of histamine. Examples include heat, cold, sunlight, water, pressure on the skin, emotional stress and exercise.
- Dermatographia (also known as dermographia). The name of this condition literally means "skin writing." Stroking or scratching the skin results in raised red lines in the same pattern as the pressure.
Hives and angioedema also occasionally occur in response to blood transfusions, immune system disorders such as lupus, some types of cancer such as lymphoma, certain thyroid conditions, and infections with bacteria or viruses such as hepatitis, HIV, cytomegalovirus or Epstein-Barr virus.
Hereditary angioedema is a rare inherited (genetic) form of the condition. It's related to low levels or abnormal functioning of certain blood proteins (C1 inhibitors) that play a role in regulating how your immune system functions.
Risk Factors
Hives and angioedema are common. You may be at increased risk of hives and angioedema if you:
-Have ahd 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
-Have ahd 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
Complications
Hives and angioedema nearly always cause:
- Itching
- Discomfort
- Difficulty breathing.
- Loss of consciousness.
- Anaphylactic shock — a serious allergic reaction involving your heart and 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.
Preparing for your appointment
You're likely to start by seeing your family doctor or primary care doctor. However, in some cases when you call to set up an appointment, you may be referred immediately to a skin disease specialist (dermatologist) or to an allergy specialist. Because appointments can be brief and there's often a lot of ground to cover, it can help to be well prepared. Here are some tips to help you get ready for your appointment and what to expect from your doctor.
What you can do
Write down your signs and symptoms, when they occurred, and how long they lasted. Also, make a list of all medications, including vitamins, herbs, supplements and over-the-counter drugs that you're taking. Even better, take the original bottles and a written list of the dosages and directions.
Write down questions that you want to ask your doctor. Don't be afraid to ask questions or to speak up when you don't understand something your doctor says. For hives and angioedema, questions you may want to ask include:
Your doctor is likely to ask you a number of questions, such as:
What you can do
Write down your signs and symptoms, when they occurred, and how long they lasted. Also, make a list of all medications, including vitamins, herbs, supplements and over-the-counter drugs that you're taking. Even better, take the original bottles and a written list of the dosages and directions.
Write down questions that you want to ask your doctor. Don't be afraid to ask questions or to speak up when you don't understand something your doctor says. For hives and angioedema, questions you may want to ask include:
- What is likely causing my symptoms?
- Are tests needed to confirm the diagnosis?
- What are other possible causes for my symptoms?
- Is my condition likely temporary or chronic?
- What is the best course of action?
- What are the alternatives to the primary approach that you're suggesting?
- Do I need prescription medication, or can I use over-the-counter medications to treat the condition?
- What results can I expect?
- Can I wait to see if the condition goes away on its own?
Your doctor is likely to ask you a number of questions, such as:
- When did you first begin experiencing symptoms?
- What did your skin reaction look like when it first appeared?
- Have your symptoms changed over time?
- Have you noticed anything that makes your symptoms worse or better?
- Do your skin lesions mainly itch, or do they burn or sting?
- Do your skin lesions go away completely without leaving a bruise or a mark?
- Do you have any known allergies?
- Have you ever had a similar skin reaction before?
- Have you tried a new food for the first time, changed laundry products or adopted a new pet?
- What prescriptions, over-the-counter medications and supplements are you taking?
- Have you started taking any new medications or started a new course of a medication you've taken before?
- Has your overall health changed recently? Have you had any fevers or lost weight?
- Has anyone else in your family ever had this kind of skin reaction? Do other family members have any known allergies?
- What at-home treatments have you used?
Test and Diagnosis
Your doctor will examine your welts or areas of swelling if they are still present and take a careful medical history to identify possible causes. Your doctor's questions may focus on recognized factors linked to urticaria and angioedema, such as certain foods, physical triggers and medications. It's important to tell your doctor about all medications you take, including over-the-counter (nonprescription) drugs and supplements, even if you don't take them every day. To help pinpoint the cause of your symptoms, your doctor may recommend that you keep a detailed diary of exposure to possible irritants. If the cause of your hives or angioedema isn't apparent from your medical history or if your symptoms persist or recur often, your doctor may recommend an allergy skin test.
- Puncture, prick or scratch (percutaneous) test. This is the type of skin test that's usually performed first. Tiny drops of purified allergen extracts are pricked or scratched into your skin's surface. This test is usually performed to identify allergies to pollen, animal dander, foods, insect venom and penicillin.
- Intradermal (intracutaneous) test. Purified allergen extracts are injected into the skin of your arm. Doctors may perform this test if they strongly suspect you're allergic to an irritant even though your puncture test is negative — especially to an irritant to which a future reaction could be life-threatening, such as insect venom or penicillin.
Treatment and Drugs
If your symptoms are mild, you may not need treatment. Many cases of hives and angioedema clear up on their own. But treatment can offer relief for intense itching, serious discomfort or symptoms that persist. The standard treatment for hives and angioedema is antihistamines, medications that reduce itching, swelling and other symptoms of histamine release.
For severe hives or angioedema, doctors may also sometimes prescribe an oral corticosteroid drug — such as prednisone — which can help lessen swelling, redness and itching.
Antihistamines
Antihistamines are divided into older, first-generation drugs and newer, second-generation medications based on their chemistry and associated side effects. Each category includes nonprescription and prescription drugs.
Second-generation, newer antihistamines. Doctors generally recommend starting treatment with these newer, second-generation drugs. For most people, these drugs are less likely to cause drowsiness or reduce your reaction time while you're driving or performing other mentally or physically demanding tasks.
Nonprescription second-generation antihistamines include:
First-generation, older antihistamines. These medications tend to make you drowsy and respond more slowly than usual while driving or performing other tasks requiring physical coordination. In addition, they may cause dry mouth, blurred or double vision, constipation or difficulty passing urine. But they may be more helpful than second-generation antihistamines for some people with hives or angioedema, especially if your symptoms are severe or involve significant swelling of your face, tongue or throat. They may also be helpful taken at bedtime if your symptoms disturb your sleep.
Nonprescription first-generation antihistamines include:
Treatment for hereditary angioedema
Antihistamines and oral corticosteroid medications — although useful in treating hives and acute angioedema — are often ineffective in treating hereditary angioedema. Medications used to treat hereditary angioedema on a long-term basis include certain androgens (male hormones), such as danazol, that help regulate levels of blood proteins.
The Food and Drug Administration (FDA) has also approved certain treatments targeting specific blood proteins that function abnormally in hereditary angioedema. These medications include:
Emergency situations
For a severe attack of hives or angioedema, you may need a trip to the emergency room and an emergency injection of adrenaline (epinephrine). If you have had a serious attack or your attacks recur, despite treatment, your doctor may prescribe — and instruct you how to use — adrenaline to carry with you for use in emergency situations.
For severe hives or angioedema, doctors may also sometimes prescribe an oral corticosteroid drug — such as prednisone — which can help lessen swelling, redness and itching.
Antihistamines
Antihistamines are divided into older, first-generation drugs and newer, second-generation medications based on their chemistry and associated side effects. Each category includes nonprescription and prescription drugs.
Second-generation, newer antihistamines. Doctors generally recommend starting treatment with these newer, second-generation drugs. For most people, these drugs are less likely to cause drowsiness or reduce your reaction time while you're driving or performing other mentally or physically demanding tasks.
Nonprescription second-generation antihistamines include:
- Loratadine (Claritin, Alavert)
- Cetirizine (Zyrtec)
- Desloratadine (Clarinex)
- Fexofenadine (Allegra)
- Levocetirizine (Xyzal)
First-generation, older antihistamines. These medications tend to make you drowsy and respond more slowly than usual while driving or performing other tasks requiring physical coordination. In addition, they may cause dry mouth, blurred or double vision, constipation or difficulty passing urine. But they may be more helpful than second-generation antihistamines for some people with hives or angioedema, especially if your symptoms are severe or involve significant swelling of your face, tongue or throat. They may also be helpful taken at bedtime if your symptoms disturb your sleep.
Nonprescription first-generation antihistamines include:
- Diphenhydramine (Benadryl, others)
- Chlorpheniramine (Chlor-Trimeton, others)
- Hydroxyzine (Vistaril)
Treatment for hereditary angioedema
Antihistamines and oral corticosteroid medications — although useful in treating hives and acute angioedema — are often ineffective in treating hereditary angioedema. Medications used to treat hereditary angioedema on a long-term basis include certain androgens (male hormones), such as danazol, that help regulate levels of blood proteins.
The Food and Drug Administration (FDA) has also approved certain treatments targeting specific blood proteins that function abnormally in hereditary angioedema. These medications include:
- Cinryze and Berinert, two treatments derived from donated human blood plasma. Both drugs provide C1 esterase inhibitor, a blood protein that's inadequate or defective in hereditary angioedema. Cinryze is approved as a therapy to prevent hereditary angioedema attacks in adults and adolescents. It's taken as an injection by vein every few days and can be self-administered after training by a health professional. Berinert is approved to treat acute hereditary angioedema attacks affecting the face and abdomen while the attacks are under way. Berinert also is taken as an injection by vein, but it must be given by a health professional.
- Ecallantide (Kalbitor) is a protein derived from yeast. It blocks the activity of a blood protein called kallikrein, which is involved in hereditary angioedema. It's approved for adolescents and adults as a treatment to counter the effects of acute hereditary angioedema attacks on all body areas. Ecallantide is taken as an injection under the skin (subcutaneous) that must be given by a health care professional.
Emergency situations
For a severe attack of hives or angioedema, you may need a trip to the emergency room and an emergency injection of adrenaline (epinephrine). If you have had a serious attack or your attacks recur, despite treatment, your doctor may prescribe — and instruct you how to use — adrenaline to carry with you for use in emergency situations.
Lifestyle and Home Remedies
If you're experiencing mild hives or angioedema, these tips may help relieve your symptoms:
- Try to identify and avoid substances that irritate your skin or that cause an allergic reaction. These can include foods, medications, pollen, pet dander, latex and insect stings.
- Use an over-the-counter antihistamine. A nonprescription oral antihistamine, such as loratadine (Claritin), cetirizine (Zyrtec) or diphenhydramine (Benadryl, others) may help relieve itching.
- Apply cool, wet compresses. Covering the affected area with bandages and dressings can help soothe the skin and prevent scratching.
- Take a comfortably cool bath. To relieve itching, sprinkle the bath water with baking soda, uncooked oatmeal or colloidal oatmeal — a finely ground oatmeal that is made for the bathtub (Aveeno, others).
- Wear loose, smooth-textured cotton clothing. Avoid clothing that's rough, tight, scratchy or made from wool. This will help you avoid irritation.
Prevention
To lower your likelihood of experiencing hives or angioedema, take the following precautions:
- Avoid known triggers. These may include certain foods or medications, or situations such as temperature extremes, that have triggered past allergic attacks.
- Keep a diary. If you suspect foods are causing the problem, keep a food diary. Be aware that some foods may contain ingredients that are listed by less common names on the label.
Hives Linked to Autoimmune Thyroid Disease
"Research reported on in the journal Dermatology found that the frequency of thyroid autoantibodies is significantly higher in patients with chronic urticaria (hives) than in healthy controls. In the study, all the patients with thyroid autoantibodies had so-called "normal" test results. Researchers concluded that there is a significant association between chronic urticaria and thyroid autoimmunity, but only the thyroid antibody tests are relevant in patients with chronic urticaria, versus thyroid function tests."
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