Haemophilia and Bleeding Disorders

von Willebrand's disease - the Calgary Guide

The most common congenital bleeding disorder.
VW Factor and Factor VIII deficiency, and abnormal platelet function
Clinically similar to platelet disorder.
Bleeding is normally mucosal and treated with Factor VIII concentrate

Haemophilia A - from the Calgary Guide

Abnormal Factor VIII which lacks clot-promoting properties
Bleeding in to deep muscles, large joints, or urinary tract.

Desmopressin raises factor VIII levels, and may be sufficient.
Tranexamic acid can help
Otherwise needs factor VIII concentrate to treat

Haemophilia B (Christmas Disease)
Deficiency of Factor XI.
Genetically and clinically indistinguishable from haemophilia A.
Factor IX concentrate to treat
Desmopressin cannot be used in the treatment of haemophilia B.

References
Oxford Handbook of Emergency Medicine
http://www.bmj.com/content/344/bmj.e2707?sso=
calgaryguide.ucalgary.ca/