Petechia

A petechia is a small (1 – 2 mm) red or purple spot on the skin or conjunctiva, caused by a minor bleed from broken capillary blood vessels. The word is derived from Latin 'petigo', meaning ‘scab' or 'eruption’. A petechia is a small (1 – 2 mm) red or purple spot on the skin or conjunctiva, caused by a minor bleed from broken capillary blood vessels. The word is derived from Latin 'petigo', meaning ‘scab' or 'eruption’. Petechia refers to one of the three descriptive types hematomas differentiated by size, the other two being ecchymosis and purpura. Ecchymosis is defined as hematomas larger than 1 centimetre and purpura as 1-5 millimetres.