Urticaria (hives) are raised red itchy areas of the skin that vary in shape and size.  They can occur any place on the body.  About 25% of Americans will experience hives at least once.  Some patients have hives that can be attributed to a specific cause such as a food or drug allergy.  Many people have hives that cannot be diagnosed as being due to an allergic reaction.  A Board Certified allergist is trained to evaluate for underlying allergies as a cause of hives and can shed light on whether or not allergies are responsible for the hives.