Hives and angioedema
Medically reviewed on March 7, 2018
Hives — also known as urticaria (ur-tih-KAR-e-uh) — is a skin reaction that causes itchy welts, which can range in size from small spots to large blotches several inches in diameter. Hives can be triggered by exposure to certain foods, medications or other substances.
Angioedema is a related type of swelling that affects deeper layers in your skin, often around your face and lips. In most cases, hives and angioedema are harmless and don't leave any lasting marks, even without treatment.
The most common treatment for hives and angioedema is antihistamine medication. Serious angioedema can be life-threatening if swelling causes your throat or tongue to block your airway.
Hives, also known as urticaria, are reddened, itchy welts that may be triggered by substances or situations, such as heat, exercise and stress.
Chronic hives appear daily or almost daily for six weeks or more.
The welts associated with hives can be:
- Red or flesh-colored
- Intensely itchy
- Roughly oval or shaped like a worm
- Less than one inch to several inches across
Most hives go away within 24 hours. Chronic hives can last for months or years.
Angioedema is a reaction similar to hives that affects deeper layers of your skin. It most commonly appears around your eyes, cheeks or lips. Angioedema and hives can occur separately or at the same time.
Signs and symptoms of angioedema include
- Large, thick, firm welts
- Swelling and redness
- Pain or warmth in the affected areas
When to see a doctor
You can usually treat mild cases of hives or angioedema at home. See your doctor if your symptoms continue for more than a few days. Seek emergency care if you feel your throat is swelling or if you're having trouble breathing.
Angioedema may cause large welts below the surface of the skin, particularly on the eyes and lips. Angioedema may also affect the hands, feet and throat.
Hives and angioedema can be caused by:
- 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 IB, others), naproxen (Aleve) and blood pressure medications.
- Common allergens. Other substances that can cause hives and angioedema include pollen, animal dander, latex and insect stings.
- Environmental factors. Examples include heat, cold, sunlight, water, pressure on the skin, emotional stress and exercise.
- Underlying medical conditions. 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, and Epstein-Barr virus.
- Genetics. Hereditary angioedema is a rare inherited (genetic) form of the condition. It's related to low levels or abnormal functioning of certain blood proteins that play a role in regulating how your immune system functions.
Hives and angioedema are common. You may be at increased risk of hives and angioedema if you:
- 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
Severe angioedema can be life-threatening if swelling causes your throat or tongue to block your airway.
To lower your likelihood of experiencing hives or angioedema, take the following precautions:
- Avoid known triggers. These can include foods, medications and situations, such as temperature extremes that have triggered hives or angioedema in the past.
- Keep a diary. If you suspect food is causing the problem but aren't sure which food is the trigger, keep a food and symptom diary.
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. In some cases, he or she may recommend an allergy skin test. He or she may order blood tests to check for levels and function of specific blood proteins if hereditary angioedema is a possible diagnosis.
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.
Treatments for hives and angioedema may include prescription drugs, including:
- Anti-itch drugs. The standard treatment for hives and angioedema is antihistamines, medications that reduce itching, swelling and other allergy symptoms.
- Anti-inflammatory drugs. For severe hives or angioedema, doctors may sometimes prescribe an oral corticosteroid drug — such as prednisone — to reduce swelling, redness and itching.
- Drugs that suppress the immune system. If antihistamines and corticosteroids are ineffective, your doctor might prescribe a drug capable of calming an overactive immune system.
- Drugs that reduce pain and swelling. Chronic hives and angioedema may be treated with a type of nonsteroidal, anti-inflammatory medication called leukotriene antagonists.
- Blood protein controllers. If you have hereditary angioedema, a variety of medications can regulate levels of certain blood proteins and relieve your signs and symptoms.
For a severe attack of hives or angioedema, you may need a trip to the emergency room and an emergency injection of epinephrine — a type of adrenaline. If you have had a serious attack or your attacks recur, despite treatment, your doctor may have you carry a pen-like device that will allow you to self-inject epinephrine in emergencies.
Lifestyle and home remedies
If you're experiencing mild hives or angioedema, these tips may help relieve your symptoms:
- Avoid triggers. These can include foods, medications, pollen, pet dander, latex and insect stings.
- Use an over-the-counter anti-itch drug. A nonprescription oral antihistamine, such as loratadine (Claritin), cetirizine (Zyrtec Allergy) or diphenhydramine (Benadryl Allergy, others), may help relieve itching.
- Apply cool, wet compresses. Covering the affected area with cool, moist bandages or 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 made for bathing (Aveeno, others).
- Wear loose, smooth-textured cotton clothing. Avoid wearing clothing that's rough, tight, scratchy or made from wool. This will help you avoid skin irritation.
Preparing for an appointment
You're likely to start by seeing your primary care doctor. 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.
What you can do
Here are some tips to help you get ready for your appointment.
- List your signs and symptoms, when they occurred and how long they lasted.
- List any medications you're taking, including vitamins, herbs and supplements. Even better, take the original bottles and a list of the doses and directions.
- List questions to ask your doctor.
For hives and angioedema, questions you may want to ask include:
- What is likely causing my symptoms?
- Do I need any tests 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?
What to expect from your doctor
Examples of questions your doctor may ask, include:
- 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?