Explanation: Urticaria, also known as hives, is an outbreak of swollen, palered bumps or plaques (wheals) on the skin that appear suddenly -- either as a result of the body's reaction to certain allergens, or for unknown reasons. Hives usually cause itching, but may also burn or sting.
8-year-old has been stung by a wasp. His skin is pale with patches of raised red spots on his hands, arms, and face.
