Abstract: Urticaria (or hives) is a skin condition, commonly caused by an allergic reaction that is characterized by raised red skin welts. It is also known as nettle rash. Hives can appear anywhere on the body, including the face, lips, tongue, throat, and ears. Rash may vary in size from about 5 mm (0.2 inches) in diameter to the size of a dinner plate; they typically itch severely, sting, or burn, and often have a pale border.