The most common location of bleeding seen in patients with von Willebrand's disease is the

• A. Spleen.
• B. Mucosal surfaces.
• C. Joint spaces.
• D. Muscle groups.

Answer: (B)

The key idea here is that von Willebrand disease causes a defect in primary hemostasis due to impaired platelet adhesion to damaged vessel walls. Von Willebrand factor normally mediates platelet sticking to exposed collagen via the GPIb receptor, so when this factor is deficient or dysfunctional, the initial platelet plug forms poorly. This leads to frequent bleeding from sites where minor trauma is common and mucous membranes are involved, making mucosal surfaces the most typical location for bleeding in von Willebrand disease. Examples include nosebleeds, gum bleeding, mouth ulcers, and heavy menstrual bleeding.

Bleeding into joints or muscles tends to be more associated with coagulation factor deficiencies (like hemophilia) rather than mucosal bleeding. Splenic bleeding is not a characteristic presentation of von Willebrand disease.