Haemophilia
Introduction
Haemophilia is an X‑linked bleeding disorder of secondary haemostasis caused by deficiency of clotting factor VIII (haemophilia A) or factor IX (haemophilia B). Clinically it predisposes to deep bleeds - haemarthrosis, muscle haematomas and life‑threatening bleeds such as intracranial haemorrhage (ICH).
Emergency management emphasises rapid recognition of red flags, early haemostatic therapy (the “treat first” principle) and immediate contact with the regional haemophilia centre or haematology team.
Genetics and epidemiology
- Haemophilia is inherited in an X‑linked recessive pattern.
- Males are typically affected; females are usually carriers and can have variable factor levels due to lyonisation.
- Haemophilia A is more common than haemophilia B.
- Acquired haemophilia (autoantibodies to factor VIII) occurs sporadically in adults and requires a different approach.
Clinical features and red flags
Typical presentations
- Recurrent spontaneous haemarthroses (knee, ankle, elbow) with pain, swelling and reduced range of motion.
- Deep muscle haematomas (iliopsoas, thigh) causing severe pain, neuropathy or blood loss.
- Excessive bleeding after minor trauma, dental work or procedures.
- Severe bleeds with minimal or no trauma in severe disease: intracranial haemorrhage, airway‑compromising head/neck haematomas, major gastrointestinal or genitourinary bleeding, expanding limb haematoma/compartment syndrome.