Thrombocytopenia Causes and Diagnosis

Major Categories of Thrombocytopenia

Bone marrow diseases, including myelodysplastic syndromes, leukemias, and other malignancies, can cause decreased platelet production 1, 2
Inherited thrombocytopenias, such as thrombocytopenia-absent radius syndrome and Wiskott-Aldrich syndrome, can also lead to decreased platelet production 1
Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by immunologic destruction of otherwise normal platelets 3
Secondary immune thrombocytopenia can be associated with autoimmune disorders, infections, and lymphoproliferative disorders 1, 4
Thrombotic microangiopathies, such as TTP-HUS, can cause increased platelet destruction 5

The initial evaluation of thrombocytopenia should include a peripheral blood smear to exclude pseudothrombocytopenia 1, 5
A complete blood count and peripheral blood smear examination are essential diagnostic tests 1
Testing for HIV and HCV is recommended in adults with typical ITP 4
Bone marrow examination may be necessary in selected cases, such as patients older than 60 years or those with systemic symptoms 1

Physical examination should be normal in primary ITP aside from bleeding manifestations 1
The presence of splenomegaly, hepatomegaly, or lymphadenopathy suggests secondary causes of thrombocytopenia 1, 5
Constitutional symptoms, such as fever and weight loss, suggest underlying disorders like infection or malignancy 1
Drug-induced thrombocytopenia should always be considered and may be difficult to exclude 5