A 40-year-old female presents with mucocutaneous bleeding and severe thrombocytopenia unresponsive to steroids. The most likely diagnosis is:

A 40-year-old female presents with mucocutaneous bleeding and severe thrombocytopenia unresponsive to steroids. The most likely diagnosis is:

• A. Decreased platelet production
• B. Suppressed pluripotent stem cells
• C. Immune thrombocytopenic purpura
• D. Defective platelet-endothelial interaction

Answer: (C)

Isolated mucocutaneous bleeding with a very low platelet count in an otherwise normal CBC points to immune-mediated destruction of platelets. In immune thrombocytopenic purpura, autoantibodies bind platelet surface glycoproteins and promote their clearance by splenic macrophages, shortening platelet lifespan and causing acute mucosal bleeding from impaired primary hemostasis. Corticosteroids are used to treat ITP, but not all patients respond, which doesn’t change the underlying mechanism. Other options involve reduced production or platelet function defects, which would present with different patterns (pancytopenia or normal platelet counts with abnormal function), making immune thrombocytopenic purpura the most fitting diagnosis.

Isolated mucocutaneous bleeding with a very low platelet count in an otherwise normal CBC points to immune-mediated destruction of platelets. In immune thrombocytopenic purpura, autoantibodies bind platelet surface glycoproteins and promote their clearance by splenic macrophages, shortening platelet lifespan and causing acute mucosal bleeding from impaired primary hemostasis. Corticosteroids are used to treat ITP, but not all patients respond, which doesn’t change the underlying mechanism. Other options involve reduced production or platelet function defects, which would present with different patterns (pancytopenia or normal platelet counts with abnormal function), making immune thrombocytopenic purpura the most fitting diagnosis.