Trombocytopenia

Trombocytopenia is a condition characterized by a platelet count below 150,000 per microliter. It can be primary (idiopathic) or secondary to another disorder.

Common causes include decreased production (bone marrow failure, nutritional deficiencies), increased destruction (immune thrombocytopenia, drug-induced immune cytopenias, infections), sequestration in an enlarged spleen, or dilutional from transfusions. Other causes include pregnancy-related alloimmune thrombocytopenia and thrombotic microangiopathies such as TTP/HUS, DIC.

Clinical features range from none to bleeding symptoms: petechiae, purpura, easy bruising, mucosal bleeding like epistaxis or gum bleeding, and heavy menses. Severe thrombocytopenia raises the risk of spontaneous bleeding, including intracranial hemorrhage.

Diagnosis relies on a complete blood count showing low platelets, often with a normal or increased mean platelet volume; a peripheral smear helps rule out pseudothrombocytopenia. Additional tests are guided by suspected cause (coagulation studies, liver and kidney function, infectious and autoimmune screens). Bone marrow examination may be needed in atypical cases or when marrow disease is suspected.

Management is cause- and severity-dependent. Mild cases may be observed. Treatments for immune thrombocytopenia include corticosteroids and intravenous immunoglobulin; refractory cases may receive rituximab, thrombopoietin receptor agonists, or splenectomy. Platelet transfusions are used for active bleeding or very low counts. Patients should avoid NSAIDs; pregnancy requires specialized guidance.