Question

Bleeding time is NOT usually prolonged in

• A. Haemophilia
• B. Secondary Thrombocytopenia
• C. Scurvy
• D. Von Willebrand's Disease

Hint:

Separate platelet-related bleeding disorders from pure coagulation factor deficiencies.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
This question tests the distinction between bleeding disorders that affect primary hemostasis (platelets and vessel wall, measured by bleeding time) and those that affect secondary hemostasis (the coagulation cascade, measured by PT/aPTT).

Step 2: Key Concept or Approach:
Bleeding time reflects how well platelets and the vessel wall form the initial platelet plug. It is prolonged in disorders of platelet number, platelet function, von Willebrand factor, or vessel wall integrity. Hemophilia, by contrast, is a deficiency of clotting factor VIII or IX affecting the intrinsic coagulation pathway; it prolongs the activated partial thromboplastin time but leaves platelet plug formation, and therefore the bleeding time, essentially normal.

Step 3: Working Through the Options:
Haemophilia does not usually prolong bleeding time because platelet function and count are normal; the defect lies purely in the coagulation cascade, making this the correct answer. Secondary thrombocytopenia reduces platelet numbers, directly impairing primary hemostasis and prolonging bleeding time. Scurvy causes vitamin C deficiency with defective collagen synthesis and weakened capillary walls, which prolongs bleeding time through a vascular mechanism. Von Willebrand's disease reduces or impairs von Willebrand factor, which is needed for platelet adhesion to the vessel wall, so bleeding time is prolonged along with a variable prolongation of aPTT.

Step 4: Conclusion:
The correct answer is haemophilia, since it is a pure coagulation factor disorder that spares platelet-mediated primary hemostasis.