Petechiae (say "pet-TEA-key-eye") are tiny, flat red or purple spots in the skin or the lining of the mouth caused by abnormal bleeding from small blood vessels that have broken close to the skin or the surface of a mucous membrane. Petechiae may spread over a large area of the body within a few hours.
Petechiae spots range from pinpoint-size to BB-size and do not itch or cause pain. They are different than tiny, flat red spots or birthmarks (hemangiomas) that are present all the time. Petechiae do not turn white when a person presses on them.
Petechiae that develop quickly over a few hours may mean that a serious infection or lack of platelets (part of the body's defense against bleeding) has developed and requires immediate medical treatment.