Hives or urticaria are itchy, often red welts that erupt on the skin. When welts develop under the skin, it is called angioedema, a condition that may occur with hives. Typically, hives are caused by an allergic reaction. Hives may appear anywhere on the body. Some hives are as tiny as a pearl or as large as a paper plate. Multiple hives can meld into one large mass as well.
Causes of hives. Hives often are caused by an allergic reaction. According to the American Academy of Dermatology, things that trigger allergic reactions resulting in hives include:
- Foods such as peanuts, tree nuts, eggs, milk, shellfish (crab, etc.) and fruits, citrus fruits in particular
- Certain medications
- Insect stings and bites
- Animal dander
- Latex or other materials
Even allergy shots can cause an allergic reaction, resulting in hives. Other things that may cause hives are exercise, scratching or prolonged pressure on the skin from staying in one position too long, and certain infections. Some people suffer from hives after sun exposure. Other elements such as cold and heat may cause hives as well. Stress can be a contributing factor to hives. A stress rash with hives may appear anywhere on the skin. Fortunately, most cases of hives disappear in about 24 hours.
Treatments for hives. Many mild/moderate hive cases can be treated with over-the-counter medicines such as antihistamines. The antihistamine will reduce the itching, making the hives bearable until they go away. Some relief may be found by applying cold compresses to the affected areas of skin or soaking in a colloidal oatmeal bath.
Chronic hives. Patients suffering from chronic hives may have to take a daily dose of a prescription antihistamine. Your doctor will work with you to determine which antihistamine will be best for your case. There are prescription antihistamine options that are non-drowsy formulas. This is important for anyone needing to remain alert for work, school or other daily activities. A dermatologist usually will perform tests to determine the cause of chronic hives. This may help him or her prescribe the best treatment to control the chronic hives.
Other medications. The AAD lists cortisones, anti-inflammatory medications and the antibacterial medication Dapsone as other medications that might be prescribed for some hive cases. Epinephrine in shot form may be injected for hives with angioedema.