Expansion
Haemophilia bleeds into joints, von Willebrand from mucosa
Expansion
The pattern of bleeding tells you the mechanism
- Platelet or vessel wall: mucocutaneous, immediate. Epistaxis, gum bleeding, menorrhagia, petechiae, purpura
- Coagulation factor: deep, delayed. Haemarthrosis, muscle haematoma, rebleeding after initial haemostasis
| Haemophilia A | Haemophilia B | von Willebrand disease | |
|---|---|---|---|
| Defect | Factor VIII | Factor IX | vWF |
| Inheritance | X-linked recessive | X-linked recessive | Autosomal dominant (usually) |
| Frequency | 1 in 5,000 males | 1 in 30,000 males | Commonest inherited bleeding disorder, 1 per cent |
| Bleeding | Deep, joints | Deep, joints | Mucosal |
| APTT | Prolonged | Prolonged | Prolonged or normal |
| PT | Normal | Normal | Normal |
| Platelets | Normal | Normal | Normal |
von Willebrand factor does two jobs, which explains the mixed picture: it mediates platelet adhesion (hence mucosal bleeding) and carries factor VIII (hence a variably prolonged APTT).
Treatment: desmopressin releases stored vWF and factor VIII, useful in mild haemophilia A and type 1 von Willebrand disease; factor concentrates otherwise; tranexamic acid for mucosal bleeding. Avoid NSAIDs and intramuscular injections.
A normal clotting screen does not exclude a bleeding disorder: mild von Willebrand disease, platelet function defects and factor XIII deficiency all have a normal screen.