Differential Diagnosis for Low Platelets

The following is a differential diagnosis for low platelets, categorized for clarity and emphasis on critical conditions.

• Single Most Likely Diagnosis

  • Immune Thrombocytopenic Purpura (ITP): This is an autoimmune disease where the body's immune system mistakenly attacks and destroys its own platelets, leading to a low platelet count. It's a common cause of isolated thrombocytopenia and often presents with petechiae, bruising, and sometimes bleeding.

• Other Likely Diagnoses

  • Viral Infections: Certain viral infections, such as HIV, hepatitis C, and some viral illnesses like mononucleosis, can lead to thrombocytopenia due to bone marrow suppression or immune system dysregulation.
  • Medication-Induced Thrombocytopenia: Several medications, including heparin, certain antibiotics, and antiplatelet drugs, can cause a decrease in platelet count as a side effect.
  • Chronic Liver Disease: Liver diseases, such as cirrhosis, can lead to splenic sequestration of platelets, resulting in thrombocytopenia.
  • Chronic Kidney Disease: Uremia associated with chronic kidney disease can affect platelet function and count.

• Do Not Miss Diagnoses

  • Thrombotic Thrombocytopenic Purpura (TTP): A rare blood disorder characterized by the formation of blood clots in small blood vessels throughout the body, which can lead to a low platelet count. It's critical to diagnose promptly due to its high mortality rate if left untreated.
  • Heparin-Induced Thrombocytopenia (HIT): An immune-mediated reaction to heparin that can cause both thrombocytopenia and a prothrombotic state, leading to potentially life-threatening thrombosis.
  • Disseminated Intravascular Coagulation (DIC): A condition characterized by both widespread clotting and bleeding in the vascular system, which can result in a low platelet count among other coagulation abnormalities. It often occurs in critically ill patients and requires immediate attention.
  • Bone Marrow Failure Syndromes: Conditions like aplastic anemia, where the bone marrow fails to produce blood cells, can lead to thrombocytopenia.

• Rare Diagnoses

  • Congenital Thrombocytopenias: A group of rare genetic disorders that affect platelet production or function, such as Bernard-Soulier syndrome and Wiskott-Aldrich syndrome.
  • Gaucher Disease: A genetic disorder where a deficiency of the enzyme glucocerebrosidase leads to an accumulation of harmful substances within cells, affecting various organs including the spleen, which can cause thrombocytopenia due to splenic sequestration.
  • Lymphoproliferative Disorders: Certain cancers like lymphoma can infiltrate the bone marrow, affecting platelet production and leading to thrombocytopenia.