Thrombotic thrombocytopenic purpura patients may develop a type of bruise or pinpoint rash referred to as petechiae. This kind of rash is best described as non-raised patches of tiny circular dots that manifest in an individual's serous or mucous membrane. These dots may be red, brown, or purple, and will not blanch or turn white when they are pressed on. Petechiae occurs when bleeding occurs underneath a patient's skin. Capillaries underneath an affected individual's skin break open and cause this type of bleeding.
The chances of spontaneous bleeding like the bleeding that causes a petechial rash are more significant in thrombotic thrombocytopenic purpura patients as a result of abnormally low platelets in the blood. Platelets are the tiny cells contained in the blood that fuse together and form clots when damaged blood vessels are discovered. Platelets keep an individual from losing an excessive amount of blood from bleeding too long. The petechial rash occurs because minor injuries to the individual's capillaries are not sealed fast enough due to platelet deficiency.