Diagnosis:
Management of ITP in Adults
• Idiopathic thrombocytopenic purpura (ITP) is a clinical diagnosis of exclusion. Patients present with isolated low platelet counts without abnormalities in the red cell and white cell lineages. Other causes of thrombocytopenia should be excluded. For example, pseudothrombocytopenia (PTCP) should be excluded by examining the peripheral blood smear.
• Bone marrow biopsy shows normal erythropoiesis and myelopoiesis and increased megakaryocytes.
• ITP is caused by autoantibodies against platelet antigens. The antibody-coated platelets are cleared by the reticuloendothelial system. Recent evidence suggests that there is a concomitant platelet production defect.
• First-line treatment of ITP includes corticosteroids, intravenous immunoglobulin (IVIG), and intravenous Rh immune globulin in Rh-positive patients. A longer course of corticosteroids is preferred over a shorter course of corticosteroids or IVIG. IVIG and Rh immunoglobulin are preferred if steroids are contraindicated.
• Second-line treatments for patients unresponsive to first-line therapy include rituximab, dapsone, and splenectomy. Splenectomy is avoided in pediatric patients because of the long-term risk of sepsis from encapsulated bacteria such as Meningococcus, Pneumococcus, and Haemophilus.
• Platelet transfusion is generally not useful because the transfused platelets are cleared at the same rate as the patient’s own platelets. However, if there is significant bleeding or bleeding risk, then platelet transfusion may be indicated.