• from platelet disorders

Etiologies-of thrombocytopenia

• Underproduction-of-thrombocytopenia
• Peripheral Destruction-of-thrombocytopenia
• Other cause-of-thrombocytopenia

↓ production

• Hypocellular bone marrow:
  • aplastic anemia (qv), rarely MDS, drugs (eg, thiazides, antibiotics, chemotherapy), alcohol, cirrhosis, viral infection
• Hypercellular bone marrow:
  • MDS, leukemia, severe megaloblastic anemia
• Marrow replacement:
  • myelofibrosis, hematologic and solid malignancies, granulomas

↑ destruction

• immune-mediated thrombocytopenia (distinguish primary from secondary; Blood 2009;113:2386)

• Non-immune-mediated:

  • MAHA (DIC, HUS, TTP),
  • ticlopidine/clopidogrel,
  • vasculitis,
  • preeclampsia/HELLP,
  • cardiopulm bypass, CVVH, IABP, cavernous hemangioma, viral

Abnormal distribution or pooling

• splenic sequestration,
• dilutional,
• hypothermia

Critical illness

• multifactorial (Hematology Am Soc Hematol Educ Program 2017;1:660)

Unknown

• ehrlichiosis/anaplasmosis 艾利希氏體症(Ehrlichiosis) 是: 蜱蟲媒介的 → 人畜共通傳染疾病，台灣過去有. 關艾利希氏體症的 → 研究較多著重在 ↣ 動物，但近年來人類感染病例逐漸浮現
• babesiosis,
• RMSF is:Rocky Mountain Spotted Fever