Purpura is sudden, severe bruising that may be localized, regional, or widespread and that occurs without an injury. People who develop purpura often have signs of illness, such as a fever, weakness, fatigue, or a vague sense of being ill (malaise).
The bruising caused by purpura is different from the isolated bruises a person often gets after bumping into an object or falling. Purpura bruises develop from within the body, rather than from an injury.
A bleeding or clotting disorder is the most common cause of purpura. Purpura that comes on quickly over a short period (a few hours) may be a sign of a serious infection that requires immediate medical treatment.