A 2 year old boy presents with continued bleeding from his mouth, following a fall 5 hours ago. Close questioning of his mother reveals a history of somewhat prolonged bleeding from immunisation sites, and other sites of minor injury. No medical attention was sought. There is no history of lethargy, weakness, or pica. His drug and family histories are unremarkable.
WBC: 7,900/mm3 (6,000 - 17,000) Hb: 12.3 g/dL (10.5 -13.5) Hct: 35.4% (33.0 - 39.0) Platelets: 368,000/mm3 (156,000 - 369,000)
PT: 11 sec (10-13) APTT: 37 sec (24-33)
vWF Ag: 0.16 U/mL (0.78-1.53) Ristocetin cofactor activity assay: <0.10 U/mL (0.50-1.50)
The peripheral blood film (blood picture) appears completely normal.