[Differential diagnosis and treatment of thrombocytopenia].

Thrombocytopenia is usually acquired. The laboratory artefact of pseudothrombocytopenia should always be excluded. Bone marrow insufficiency with impaired platelet production results from infiltrating tumor cells or from a myelodsplastic syndrome. In patients with splenomegaly, platelets are trapped by the spleen. An increased platelet turnover is caused by activation of the clotting cascade, e.g. due to sepsis or malignancy. Platelet binding antibodies cause thrombocytopenia by increased platelet clearance. Important differential diagnoses in patients with severe thrombocytopenia are: acute leukemia, thrombotic thrombocytopenic purpura, autoimmune thrombocytopenia and drug-dependent thrombocytopenia. Multifactorial causes are thrombocytopenia associated with pregnancy, chronic alcohol abuse, and liver cirrhosis. Treatment should focus on the underlying disease. In regard to low platelet counts only clinical bleeding and not platelet count numbers should be treated.