Purpura thrombocytopenicM31.1; M69.61(Thrombozytopenie)

Polyätiological, microangiopathic, mostly small spotted purpura (petechiae) caused by thrombocytopenia of varying aetiology and severity.

Causes of thrombocytopenia include:

• Formation defects:
  • Decreased megakaryocytopoiesis:
    • Congenital
    • Acquired: E.g., by drugs, radiation therapy, chemicals, viruses, bacterial infections.
    • Displacement: E.g., by bone marrow carcinomatosis, leukemias, malignant lymphomas (e.g., plasmacytoma), osteomyelofibrosis.
  • Ineffective thrombocytopoiesis: E.g. Wiskott-Aldrich syndrome.
• Increased depletion or consumption:
  • Immunologic:
    • Primary autoantibody formation: E.g. idiopathic thrombocytopenic purpura.
    • Secondary autoantibody formation: E.g. drugs, collagenoses, immune complex diseases, antiphospholipid antibody syndrome).
  • Non-immunologic:
    • E.g. disseminated intravascular coagulation.
• Distribution disorders:
  • E.g., platelet pooling in the spleen in splenomegaly.

The clinical picture of thombopenic purpura (platelet count <140,000/ul) is characterized by orthostatic, indistinct, (fine-spotted - nonpalpable) petechial hemorrhages (hemorrhage: verification by diascopy - easily performed by firm thumb compression of the skin ). Capillary damage is often present at the same time. In case of a recurrent course of the orthostatic petechial hemorrhages, there are two-dimensional pigmentations due to hemosiderin deposits.

In advanced thrombocytopenia, there may be planar hemorrhages. Linear patterns in scratch marks (purpura factitia) are also possible. In these cases, clarification of an existing coagulation disorder is always required.

Frequently, thrombocytopenia is not known, as there is usually no risk of bleeding as long as the number of functional thrombocytes is > 30,000/ul and plasmatic coagulation is normal.

Varies depending on the triggering cause.

Avoidance of a triggering drug. Depending on the clinic and platelet count, systemic glucocorticoids are indicated, e.g. prednisone (e.g. Decortin) initially 100 mg/day, gradual reduction according to clinic.

The treatment of thrombocytopenia is a treatment to be performed under internistic control.

The thrombocytopenic purpura should not be confused with the Moschcowitz syndrome, the thrombotic thrombocytopenic purpura.