Hives appear as "wheals" (swellings) on the skin, sometimes pink or red and surrounded by a red blotch. Typically round or oval, hives often itch. Hives vary in size, and some may blend to form larger areas of swelling. Hives can affect skin on any area of the body, especially the trunk, thighs, upper arms and face. Most individual hives fade quickly, but new crops may appear every 24 to 72 hours if the person continues to be exposed to the environment or substance that triggered the hives.
If hives are an early sign of a whole-body reaction, other symptoms to look for include swelling of the tongue, lips or face; wheezing; dizziness; chest tightness; and breathing difficulties. If these symptoms occur, get immediate medical attention. You could be developing anaphylaxis, a life-threatening condition.