Hematopathology

Petechiae are minute (1- to 2-mm) hemorrhages into skin, mucous membranes, or serosal surfaces. Purpura is raised slightly larger than petechiae (3- to 5-mm) hemorrhages and can be associated with many of the same disorders that cause petechiae. Ecchymoses are larger (1- to 2-cm) subcutaneous hematomas (bruises)
Petechiae, Purpura & ecchymoses