Hives or urticaria can be defined as a red rash with itching, swelling and elevation of the skin.  Hives can be accompanied by more severe swelling which can occur underneath the skin, especially in the soft tissues around the eyes, lips, hands and feet.  This form of swelling is refered to as angioedema.  Hives and angioedema may occur alone or together.  Both may occur suddenly in the form of a reaction to a drug such as penicillin, an infection such as hepatitis, or after a sting by an insect.  Certain foods such as eggs, peanuts, tomatoes, walnuts and fish can cause allergic reactions, which can be manifested by the appearance of hives and angioedema.
The vast majority of patients who come to the allergist’s office with hives have suffered with them almost on a daily basis for six weeks or more.  Often in these cases, no underlying cause such as food, infection or drug reaction can be identified.  This form of long lasting or chronic hives usually is well controlled with antihistamines.  Large studies performed on patients with chronic hives have rarely found an association with underlying serious diseases.  Most patients with this condition can be reassured that this problem will not continue forever as they will usually improve within a period of five years.
On your initial visit, the allergist will take a careful history and perform a physical examination.  This is done to exclude some forms of underlying illnesses.  The allergist will also perform certain laboratory tests, which are used primarily as screening tools to rule out any underlying disorders.  Treatment is usually begun with antihistamines.  Atarax (hydroxyzine), Benadryl, Claritin, Zyrtec, and Allegra are effective antihistamines used for the initial treatment of hives.  If one antihistamine does not seem to work, another may be substituted at some time during the course of treatment.  In some situations in which certain foods are suspected of causing hives, your doctor may ask you to keep a food diary in order to identify the unsuspected foods that may be contributing to the problem.
Some patients may experience the onset of their hives following exposure to extreme cold or sunlight, during exercise, or following direct pressure on the skin (for example, from a tight belt or bra strap).  In these particular situations, in may be wise to avoid those physical factors that are known to provoke hives.
In most cases, with the appropriate medication and avoidance measures, hives and angioedema can be controlled to the satisfaction of both the patient and the physician.