Haemophilia

What it is

Haemophilia A is FVIII deficiency and haemophilia B is FIX deficiency. Both are X-linked recessive: A in 1/5,000 males, B in 1/30,000 males. Clinical and laboratory features are identical in the two, except that it is Factor IX that is decreased in B.

Haemophilia A is divided by the factor level, and the level decides the treatment:

• Mild: >5% of normal factor level
• Moderate: 1-5%
• Severe: <1%

How it presents

The bleeding is of the secondary, coagulation pattern, and setting it beside the primary platelet and VWF pattern is what makes it clear:

• Surface cuts: normal or slightly prolonged bleeding, where a primary problem gives excessive, prolonged bleeding
• Onset after injury: delayed, where a primary problem bleeds immediately
• Site of bleeding: deep, that is joints and muscles, with excessive post-traumatic bleeding, where a primary problem bleeds superficially, from mucosal sites such as nasal, gingival, GI tract and vaginal, and from skin
• Lesions: hemarthroses and hematomas, where a primary problem gives petechiae and ecchymoses

So the picture is a young man with recurrent bruising, hematuria and hemarthroses.