Purpura (from the Latin, purpura, meaning 'purple') is the appearance of red or purple discolorations on the skin that do not blanch on applying pressure. They are caused by bleeding underneath the skin. Purpura measure 0.3-1 cm, whereas petechiae measure less than 3 mm, and ecchymoses greater than 1 cm. Purpura is a common, unspecific medical signs however the underlying mechanism commonly involves either a platelet disorder, a vascular disorder or a coagulation disorder. They commonly appear with meningitis or meningococcal sepsis.