Differential Diagnosis for Low Platelet Count

Single Most Likely Diagnosis

• Immune Thrombocytopenic Purpura (ITP): This condition is characterized by the production of antibodies against platelets, leading to their destruction. It is a common cause of low platelet count and often presents with petechiae, bruising, and sometimes bleeding.

Other Likely Diagnoses

• Viral Infections: Certain viral infections, such as HIV, hepatitis C, and Epstein-Barr virus, can lead to a low platelet count due to bone marrow suppression or immune-mediated platelet destruction.
• Medication-Induced Thrombocytopenia: Various medications, including heparin, quinine, and sulfonamides, can cause thrombocytopenia as a side effect, either through immune-mediated mechanisms or direct toxicity to platelets or megakaryocytes.
• Chronic Liver Disease: Liver cirrhosis can lead to splenic sequestration of platelets, resulting in thrombocytopenia, due to portal hypertension.
• Disseminated Intravascular Coagulation (DIC): Although more commonly associated with a consumption coagulopathy, DIC can also present with thrombocytopenia due to the consumption of platelets in the formation of microthrombi.

Do Not Miss Diagnoses

• Thrombotic Thrombocytopenic Purpura (TTP): A rare but life-threatening condition characterized by thrombocytopenia, microangiopathic hemolytic anemia, renal failure, neurological symptoms, and fever. Prompt diagnosis and treatment are crucial to prevent high mortality.
• Heparin-Induced Thrombocytopenia (HIT): An immune-mediated reaction to heparin that can lead to severe thrombocytopenia and paradoxical thrombosis, making it critical to recognize and manage promptly.
• Severe Sepsis: Sepsis can cause thrombocytopenia through various mechanisms, including consumption, bone marrow suppression, and endothelial damage. Recognizing and treating the underlying infection is vital.

Rare Diagnoses

• Congenital Thrombocytopenias: A group of rare genetic disorders affecting platelet production or function, such as Bernard-Soulier syndrome and Wiskott-Aldrich syndrome.
• Bone Marrow Failure Syndromes: Conditions like aplastic anemia and myelodysplastic syndromes can lead to thrombocytopenia due to a failure of the bone marrow to produce sufficient platelets.
• Gestational Thrombocytopenia: A condition occurring during pregnancy, characterized by mild thrombocytopenia, typically resolving after delivery.
• May-Hegglin Anomaly: A rare genetic disorder affecting platelet function and morphology, often associated with thrombocytopenia and characteristic inclusion bodies in neutrophils.