Marrow infiltration (tumor or infection)
Viral infections (rubella, HIV)
Marrow suppression (commonly chemotherapy or radiation)
Congenital<unk> 
Fanconi anemia
Alport syndrome
Bernand Soulier
Vitamin B12 and/or folate deficiency
Fanconi anemia
Alport syndrome
Bernand Soulier
Idiopathic<unk><unk> 
Thrombotic<unk><unk>  (TTP)
Hemolytic Uremic Syndrome (HUS)
Disseminated Intravascular Coagulation (DIC)
Viral infections (HIV, mumps, varicella, EBV)
Drugs (heparin, protamine)
Postransfusion or Posttransplantation
Autoimmune destruction (SLE or Sarcoidosis)
Mechanical destruction
Artificial valves
ECMO
HELLP syndrome
Excessive hemorrhage
Hemodialysis, extracorporeal circulation
Splenic Sequestration
Occurs in Sickle cell disease and Cirrhosis
Artificial valves
ECMO
Occurs in Sickle cell disease and Cirrhosis
sulfa antibiotics, ETOH, ASA, thiazide diuretics/furosemide
Abnormal platelet count and/or coagulation
Septicemia
Idiopathic<unk><unk>  <unk> 
Hemolytic uremic syndrome
Leukemia
Coagulopathies (e.g. hemophilia)
Henoch-Schonlein<unk>  (HSP)
Acute hemorrhagic edema of infancy (AHEI)
Hypersensitivity vasculitis
Primary vasculitides
Wegener's
Microscopic polyangiitis
Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)
Secondary vasculitides
Henoch-Schonlein<unk> 
Connective tissue disorder
Systemic lupus erythematosus
Scurvy
Infectious disease
Hepatitis B
Hepatitis C
Trauma
Septicemia
Idiopathic<unk><unk>  <unk> 
Hemolytic uremic syndrome
Leukemia
Coagulopathies (e.g. hemophilia)
Henoch-Schonlein<unk>  (HSP)
Acute hemorrhagic edema of infancy (AHEI)
Wegener's
Microscopic polyangiitis
Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)
Henoch-Schonlein<unk> 
Connective tissue disorder
Systemic lupus erythematosus
Scurvy
Infectious disease
Hepatitis B
Hepatitis C
Systemic lupus erythematosus
Hepatitis B
Hepatitis C
Immune thrombocytopenic purpura
Marrow infiltration 
Thrombotic thrombocytopenic purpura
Viral infections 
Disseminated intravascular coagulation
Marrow suppression 
Heparin-Induced Thrombocytopenia 
Congenital thrombocytopenia