Haemophilia

Question 1

What is the definition of haemophilia?

Answer 1

An X-linked recessive, hereditary disorder in which abnormally prolonged bleeding recurs episodically at one or a few sites on each occasion.

Question 2

What causes haemophilia A?

Answer 2

Factor VIII deficiency

Question 3

What causes haemophilia B?

Answer 3

Factor IX deficiency

Question 4

What type of haemophilia is more common?

Answer 4

Haemophilia A (5x as common)

Question 5

What is the pathophysiology of haemophilia?

Answer 5

No abnormality of primary haemostasis
Bleeding from medium to large blood vessels, most commonly into joints
Severity of affected families depends on factor VIII/IX level involved

Question 6

What are some clinical features of haemophilia?

Answer 6

Mild
- Bleeding only after injury or surgery

Severe
- Recurrent haemoarthrosis
- Recurrent soft tissue bleeds (bruising)
- Prolonged bleeding after dental extractions, surgery, invasive procedures

Question 7

What are some investigations for haemophilia?

Answer 7

Bloods:
- Isolated prolonged APTT
- Coagulation factor assays (factor VIII for A, factor IX for B)
Genetic testing

Question 8

What is the management of haemophilia?

Answer 8

Acute bleeding/prevention of excessive bleeding during procedures:
- Desmopressin for minor bleeds
- Infusions of affected factor for major bleeds
- Antifibrinolytics (tranexamic acid) for bleeding wounds but not muscle haematomas/haemarthrosis/urinary bleeding due to fibrosis

Supportive management:
- Vaccination against hepatitis B
- Hydrotherapy
- Orthopaedic and dental advice