What are Hives/Urticaria?
Hives, also known as urticaria, are an outbreak of swollen, pale red bumps, patches, or welts that appear suddenly on the skin. Hives usually cause itching, but may also burn or sting.
Hives can last for a few hours or days, and can appear anywhere on the body, including the face, lips, tongue, throat, or ears.
Hives vary in size (from a pencil eraser to a dinner plate), and may join together to form larger areas, known as plaques.
What is Angioedema?
Angioedema are similar to hives, but the swelling occurs beneath the skin, instead of on the surface. Angioedema is characterized by deep swelling around the eyes, lips and sometimes swelling of the genitals, hands, and feet.
Angioedema generally last longer on the body than hives – approximately 24 hours.
Occasionally, severe and prolonged tissue swelling can be disfiguring. Rarely, angioedema of the throat, tongue, or lungs can block the airways, causing difficulty breathing, which may become life threatening.
What Causes Hives and Angioedema?
It is nearly impossible to determine the direct cause of Hives and Angioedema in most patients. Hives and Angioedema form in response to histamine and from blood plasma that leaks out of small blood vessels in the skin.
Histamine is a chemical released from specialized cells along the skin’s blood vessels. Allergic reactions to chemicals in foods, insect stings, sunlight exposure, or medicines can all cause histamine release, which, in turn, cause hives or angioedema.
How are Hives and Angioedema Diagnosed?
Your doctor will conduct a detailed medical interview to find the possible cause of hives or angioedema. Since there is no specific test for diagnosing hives – or the associated swelling of angioedema – testing will depend on your medical history and a thorough examination by your primary doctor, allergist, immunologist, or dermatologist.
Skin tests may be performed to determine the substance that is causing your symptoms to present. Routine blood tests are done to determine if a system-wide illness is present.
How Can Hives be Managed?
There are a number of tactics you can use to help minimize your discomfort:
- Avoid hot water; use lukewarm water instead
- Use gentle, mild soap
- Apply cool compresses or wet cloths to the affected areas
- Try to work and sleep in a cool room
- Wear loose-fitting lightweight clothing
When Should I Contact a Physician?
If hives or Angioedema occur with any of the following symptoms, contact your doctor right away:
- Difficulty breathing
- Tightness in the chest
- Swelling of the tongue, lips, or face
Types of Hives and Angioedema
Acute Urticaria and/or Angioedema
Hives or swelling lasting less than six weeks. The most common causes are foods, medicines, latex, or infections. Insect bites and internal disease may also be responsible. Certain food additives and preservatives may also be to blame. Drugs that can cause hives include aspirin and other non-steroidal anti-inflammatory medications (NSAIDs, such as ibuprofen), high blood pressure medications (ACE inhibitors), or painkillers, such as codeine.
Chronic Urticaria and/or Angioedema
Hives or swelling lasting more than six weeks. The cause of this type of hives is usually more difficult to identify than those causing acute urticaria and/or angioedema. The causes can be similar to those of acute urticaria but can also include autoimmunity, chronic infections, hormonal disorders, and malignancy.
Hives caused by direct physical stimulation of the skin such as exposure to cold, heat, sun, vibration, pressure, sweating, and exercise. The hives usually occur right where the skin was stimulated and rarely appear anywhere else. Hives can appear within an hour of the initial exposure.
Hives that form after firmly stroking or scratching the skin. These hives can also occur along with other forms of urticaria.
Hereditary angioedema is painful swelling of bodily tissue that is passed on genetically through families.