Table 2. Differential Diagnosis and Diagnostic Features of Quantitative Platelet Disorders
Mechanism of ThrombocytopeniaDifferential DiagnosisComments
Impaired productionHematologic malignancies20Often accompanied by abnormalities in other marrow cell lines (ie, red and white blood cells)
Aplastic anemia41Other marrow cell lines affected as well
Myelodysplasia20May be accompanied by abnormalities in other marrow cell lines; bleeding may occur at higher platelet counts than expected
Drugs/toxins41,42For example, alcohol, chemotherapeutic agents, radiation
Viral marrow suppression or damage42For example, because of EBV, parvovirus, HCV, or HIV
Gestational thrombocytopenia43Generally mild [ie, platelet count >70,000/mL] and self-limited, resolving after delivery; exact mechanism of thrombocytopenia unknown—hemodilution and increased platelet turnover may also contribute
Liver disease42Because of reduced levels of thrombopoietin, which is produced by the liver
Nutritional deficiencies42For example, folate, vitamin B12
Inherited thrombocytopenias16,17,19,41Often present with incidental thrombocytopenia in adulthood; may have family history of thrombocytopenia or personal history of low platelet counts
Destruction or consumptionImmune
Medication, including heparin (most common), various antimicrobial, antiarrhythmic, anticonvulsant, and antifungal agents, and H2 receptor antagonists41
ITPAlong with drug-induced thrombocytopenia, accounts for majority of isolated thrombocytopenia in adults16; typically chronic in adults41; may occasionally be accompanied by Coombs positive hemolytic anemia [Evans syndrome]41
Autoimmune disease41
Infection41,45For example, HIV
TTP in presence of ADAMTS13 autoantibodies41,46Coombs-negative hemolytic anemia and thrombocytopenia; may or may not have associated renal insufficiency, fever, and mental status changes; neurological symptoms vary, ranging from headache and confusion to seizures and stroke-like symptoms
HUSRelatively uncommon but life-threatening cause of thrombocytopenia; classic form consists of microangiopathic hemolytic anemia, thrombocytopenia, and renal failure
DIC41Other hallmark laboratory findings include decreased fibrinogen, elevated fibrin degradation products, and a positive D-dimer
HELLP syndrome44Serious intrapartum condition characterized by hemolysis and elevated liver enzymes in addition to thrombocytopenia; frequently coexists with preeclampsia; may recur in subsequent pregnancies
Physical destruction41,42For example, valvular disease, cardiopulmonary bypass, cavernous hemangiomas (eg, in Kassabach-Merritt syndrome)
  • ADAMTS, a disintegrin and metalloproteinase with thrombospondin type 1 motives; DIC, disseminated intravascular coagulation; EBV, Epstein-Barr virus; HCV, hepatitis C virus; HELLP, hemolysis, elevated liver enzymes, and low platelets; HIV, human immunodeficiency virus; HUS, hemolytic uremic syndrome; ITP, idiopathic thrombocytopenic purpura; TTP, thrombotic thrombocytopenic purpura.