Formally known as urticaria, hives are suddenly occurring swollen, pinkish-red bumps on the skin. These bumps may be very small (about the size of a pinhead), very large (about the size of a dinner plate, or anywhere in between. They may appear anywhere on the body, including the lips, tongue, or throat. Hives are usually itchy, but may also be accompanied by a burning or stinging sensation. An individual hive often lasts less than 24 hours, but an old hive may be replaced by a new hive, allowing an outbreak to persist for much longer.
Acute hives, which last less than six weeks, are most often a histamine reaction, a specific type of immune response. This sort of reaction may be caused by exposure to an allergen, insect stings or bites, chemicals in certain foods (even when an allergy is not present), exposure to sunlight, and/or certain medications. Acute hives may also be caused by direct physical stimulation of the skin – massage, cold, heat, and even sweating may cause acute hives. Chronic hives last for six weeks or longer. The cause of chronic hives may be extremely difficult to pin down for many patients. Potential causes include thyroid disease, hepatitis, infection, or some forms of cancer. This is a small sampling of potential causes and by no means a complete list.
Treatment of hives depends on the cause. If the patient has no known allergies, an allergy skin test may be performed to determine a possible cause. Routine blood tests may determine if there is an underlying chronic condition causing the hives. Regardless of the cause, the best treatment for symptoms is usually antihistamines. Your doctor may write you a prescription or recommend an over-the-counter antihistamine. Chronic hives may require stronger medications, such as corticosteroids. In extreme cases, an epinephrine shot may be needed. Additional at home relief for hives may include applying cold compresses to affected areas, working and sleeping in cool rooms, and wearing lightweight, loose-fitting clothing.