How do you diagnose bleeding disorders of unknown cause (BDUC)?¶
Answer:
- The first step is a bleeding history and family history, using standardized tools such as the ISTH-BAT or MCMDM-1 BAT — to document the bleeding history, standardize communication, improve post-test probability, and outline the extent of testing.
- BDUC definition, from the ISTH SSC communication:
To diagnose bleeding disorder of unknown cause (BDUC), normal complete blood count, prothrombin time, activated partial thromboplastin time, thrombin time, von Willebrand factor antigen, von Willebrand factor function, coagulation factors VIII, IX, and XI, and platelet light transmission aggregometry should be the minimum laboratory assessment.
— Standardization of definition and management for BDUC: communication from the SSC of the ISTH
- There is still uncertainty in how to approach these patients, given the limited evidence on testing.
- Around 50–60% may have no identifiable defect on hemostatic testing.
- See the review below for a proposed management approach.