<prompt> Thrombocytopenia is caused by: -AspirinAcyclovirDICHenoch-schonlein purpura HSP  <response>: Causes of thrombocytopenia: I. -Decreased production of platelets: 1selective impairment of platelet production: adrug induced : alcohol , thiazides . b Infections : measles, HIV .Disseminated intravascular coagulation DIC occurs as a complication of a wide variety of disorders. DIC is caused by the systemic activation of coagulation and results in the for- mation of thrombi throughout the microcirculation. As a conse- quence, platelets and coagulation factors are consumed and, secondarily, fibrinolysis is activated. Thus, DIC can give rise to either tissue hypoxia and microinfarcts caused by myriad microthrombi or to a bleeding disorder related to patho- logic activation of fibrinolysis and the depletion of the ele- ments required for hemostasis hence the term consumptive coagulopathy. This entity probably causes bleeding more commonly than all of the congenital coagulation disorders combined. 2nutritional deficiency: B12 and folate deficiency. 3 Bone marrow failure: aplastic anemia 4 Bone marrow replacement: Leukemia , disseminated cancer 5Infective hematopoiesis:MDS II. -Decreased platelet survival 1 immunologic destruction: aprimary autoimmune:ac cc immune thrombocytopenic purpura. b secondary autoimmune:SLE, B-cell lymphoid neoplasms, Alloimmune , drug induced : quinidine , heparin ,sulfa compounds.,infections:HIV , IMN. 2non immunologic destruction: DIC, thrombotic microangiopathies , giant hemangiomas. III.- Sequestration: Hypersplenism IV. -Dilution :Transfusions Ref :Robbins pathologic basis of disease ; south east asia edition-9 ;pg450:table: 14-9. 