The important role of platelets in hemostasis is to form the temporary hemostatic plug, primarily requiring a sufficient number of platelets. When a quantitative reduction of platelets exists, it can result in a significant cause of generalized bleeding. Patients presenting with a platelet count of less than 100,000 cells/mm3 are diagnosed with thrombocytopenia. When the platelet count is under 50,000 cells/mm3, bleeding will be excessive postoperatively; thus, a platelet transfusion may be necessary prior to invasive treatment. Moderate to severe thrombocytopenia (less than 50,000 cells/mm3) is usually manifested by petechiae in the skin or on the mucous membranes; purpura or ecchymoses on the skin; spontaneous mucosal bleeding; or intracranial hemorrhage.1,5 In the oral cavity, bleeding gingiva is a common sign, spontaneous bleeding associated with brushing or flossing may be observable, and bleeding from teeth extractions is possible. This condition is diagnosed by a platelet count laboratory test, or by a complete blood count (CBC). Depending on the cause, thrombocytopenia can be a consequence of increased platelet destruction, decreased platelet production, decreased platelet survival, or increased splenic sequestration.5

Thrombocytopenia is the leading cause of bleeding disorders, as presented in the following major categories.

Causes of Decreased Production of Platelets1,9

  • Generalized diseases of the bone marrow
    • Aplastic anemia
  • Drug-induced thrombocytopenia
    • Cytotoxic drugs
    • Alcohol
    • Thiazide diuretics
  • Infections: measles, HIV
  • Ineffective megakaryopoiesis

Causes of Platelet Destruction or Decreased Platelet Survival1,9

  • Immunologic destruction
    • Immune thrombocytopenic purpura (ITP)
    • Infections
      • HIV, infectious mononucleosis, cytomegalovirus (CMV)
    • Drug-associated
      • Quinine or quinidine
      • Methyldopa
      • Sulfonamides
      • Heparin
      • Gold
      • D-penicillamine
      • Þ-aminosalicylic acid
  • Nonimmunologic destruction
    • Thrombotic thrombocytopenic purpura
    • Giant hemangiomas
    • Hemolytic anemias