Which condition features prolonged bleeding time and decreased platelet count, with prothrombin time and partial thromboplastin time unaffected?

Which condition features prolonged bleeding time and decreased platelet count, with prothrombin time and partial thromboplastin time unaffected?

• A. Aspirin
• B. Thrombocytopenia
• C. Haemophilia
• D. Von Willebrand disease

Answer: (B)

Bleeding time reflects how quickly a platelet plug forms. When platelet numbers are low, or platelets don’t function well, this initial plug formation is slowed, so bleeding time is prolonged. Prothrombin time and partial thromboplastin time assess the coagulation cascade factors, not platelets, so they remain normal if the issue is just a shortage of platelets. Thrombocytopenia fits this pattern: fewer platelets means longer bleeding time, while the coagulation factor pathways (measured by PT and aPTT) are unaffected. Aspirin would prolong bleeding time by impairing platelet function, but it doesn’t reduce platelet count. Hemophilia involves a deficiency in clotting factors and typically lengthens the aPTT rather than the bleeding time. Von Willebrand disease can prolong bleeding time due to defective platelet adhesion and can also affect aPTT via reduced factor VIII, so the pattern with all times remaining unaffected doesn’t align as well.

Bleeding time reflects how quickly a platelet plug forms. When platelet numbers are low, or platelets don’t function well, this initial plug formation is slowed, so bleeding time is prolonged. Prothrombin time and partial thromboplastin time assess the coagulation cascade factors, not platelets, so they remain normal if the issue is just a shortage of platelets. Thrombocytopenia fits this pattern: fewer platelets means longer bleeding time, while the coagulation factor pathways (measured by PT and aPTT) are unaffected.

Aspirin would prolong bleeding time by impairing platelet function, but it doesn’t reduce platelet count. Hemophilia involves a deficiency in clotting factors and typically lengthens the aPTT rather than the bleeding time. Von Willebrand disease can prolong bleeding time due to defective platelet adhesion and can also affect aPTT via reduced factor VIII, so the pattern with all times remaining unaffected doesn’t align as well.