RT Book, Section A1 Alexandrescu, Doru T. A1 Levi, Marcel A2 Kaushansky, Kenneth A2 Prchal, Josef T. A2 Burns, Linda J. A2 Lichtman, Marshall A. A2 Levi, Marcel A2 Linch, David C. SR Print(0) ID 1178754889 T1 The Vascular Purpuras T2 Williams Hematology, 10e YR 2021 FD 2021 PB McGraw-Hill Education PP New York, NY SN 9781260464122 LK hemonc.mhmedical.com/content.aspx?aid=1178754889 RD 2024/10/08 AB SUMMARYPurpura, the clinical manifestation of blood extravasation into mucosa or skin, results from various conditions, including rheumatologic, infectious, dermatologic, traumatic, and hematologic disorders. This chapter does not detail purpura resulting from quantitative or functional defects in hemostasis and coagulation, such as deficiencies of platelets or coagulation factors; these causes are discussed in other chapters (eg, thrombocytopenia in Chap. 116, coagulation factor deficiencies in Chaps. 122 and 123).The differential diagnosis of the disparate causes of noncoagulopathic purpura is best approached by stratifying purpura into three types of lesions: (1) palpable or retiform and noninflammatory, such as hyperglobulinemic purpura of Waldenström; (2) palpable or nonpalpable but inflammatory, such as Henoch-Schönlein purpura; and (3) nonpalpable and noninflammatory, such as senile purpura. By accounting for palpability, presence of inflammation, size, and shape, the differential diagnosis of a particular lesion can be significantly reduced.