RT Book, Section A1 Lichtman, Marshall A. A1 Kaushansky, Kenneth A1 Prchal, Josef T. A1 Levi, Marcel M. A1 Burns, Linda J. A1 Armitage, James O. SR Print(0) ID 1133365940 T1 The Vascular Purpuras T2 Williams Manual of Hematology, 9e YR 2017 FD 2017 PB McGraw-Hill Education PP New York, NY SN 9781259642470 LK hemonc.mhmedical.com/content.aspx?aid=1133365940 RD 2024/03/19 AB Purpura is the extravasation of red cells from vasculature into the skin and/or subcutaneous tissues.Petechiae are red-purple lesions less than 2 mm in diameter.Purpura describes red-purple lesions 2 mm to 1 cm.Ecchymoses are red-purple lesions greater than 1 cm.Erythema is reddened skin due to increased capillary flow.Telangiectasia is dilated superficial capillaries.Erythema and telangiectasia blanch with pressure, and petechiae and purpura do not. This can be easily demonstrable with a glass microscope slide.