1 learning resource available for this topic
Thrombocytopenia is a condition characterized by abnormally low platelet counts (<150,000/μL), leading to increased bleeding risk and petechial rashes. The four major causes include immune thrombocytopenic purpura (ITP), thrombotic thrombocytopenic purpura (TTP), hemolytic uremic syndrome (HUS), and disseminated intravascular coagulation (DIC), each with distinct pathophysiologic mechanisms and clinical presentations.
ITP involves autoimmune destruction of platelets by antiplatelet antibodies, while TTP results from ADAMTS13 deficiency causing microthrombi formation and platelet consumption. HUS typically follows infections (especially E. coli O157:H7) causing endothelial damage and localized thrombosis primarily in kidneys, whereas DIC represents widespread activation of coagulation cascades leading to both thrombosis and bleeding due to consumption of clotting factors and platelets.
Diagnosis requires careful evaluation of platelet count, peripheral blood smear, and associated symptoms to differentiate between causes. ITP presents with isolated thrombocytopenia and mucocutaneous bleeding, TTP shows the classic pentad (thrombocytopenia, hemolytic anemia, neurologic symptoms, fever, renal dysfunction), HUS manifests with the triad of thrombocytopenia, hemolytic anemia, and acute kidney injury, while DIC demonstrates both bleeding and clotting with consumption of multiple coagulation factors. Treatment approaches vary significantly, from corticosteroids in ITP to plasmapheresis in TTP, supportive care in HUS, and addressing underlying causes in DIC.