Hives (Urticaria) are red or white itchy bumps that appear on the skin. Hives result from allergic reactions, environmental factors, and certain medical conditions. In many cases, hives resolve without medical treatment. Over-the-counter or prescription medications are the standard treatments for hives.
Your immune system usually fights germs to keep you healthy. If you have allergies, your immune system overreacts to ordinary substances that normally are not harmful, such as pollen or certain foods. The substances that trigger an allergic reaction are called allergens. When you are exposed to an allergen, your white blood cells produce antibodies. The antibodies trigger the release of histamine and other chemicals in your blood called mediators. The mediators can cause hives to appear on the skin. Deep hives that are located on the face near the eyes or lips are termed angioedema.
Hives can be caused by exposure to allergens, such as foods, animal dander, medications, latex, pollen, and insect bites. Environmental factors, including sun exposure, hot or cold temperature, water, excessive perspiration, emotional stress, exercise, or skin pressure, can cause hives. Infections, thyroid disorders, blood transfusions, lupus, cancer, hepatitis, and the common cold are examples of medical conditions that can cause hives.
Hives are red or white welts (wheals) that appear on the skin. Deeper welts on the face are termed angioedema. You may have one welt or a group of welts. The welts may itch, burn, or sting.
The welts may come and go. Hives can last as long as a day or weeks. Chronic hives last more than six weeks, and in some cases for months or years.
Your doctor can diagnose hives by reviewing your medical history and examining your skin. An allergist can conduct a skin test or blood test to identify the substances that cause your allergic reactions.
In many cases, hives go away without treatment. Over-the-counter or prescription antihistamine medication is commonly recommended. Corticosteroid medications may be prescribed for severe hives. The hereditary type of hives is treated with androgen medications.
You should avoid the allergens or triggers that cause your hives. It can be helpful to wear loose-fitting cotton clothing. A cool wet compress or bath with baking soda and finely ground oatmeal can help ease symptoms.
Am I at Risk
You may be at risk for hives if you have:
had hives before.
experienced allergic reactions.
a medical condition that can cause hives.
family members that get hives.
been exposed to allergens or triggers that cause your hives.
A severe case of hives may require emergency medical treatment. You should go to the emergency department of a hospital if you experience difficulty breathing or a swollen throat or swollen airway. Your doctor may recommend that you carry an emergency shot of adrenaline (epinephrine) or steroids.