How can I differentiate between von Willebrand disease and other bleeding disorders in a patient with a family history of bleeding?

To differentiate von Willebrand disease (VWD) from other bleeding disorders in a patient with a family history of bleeding, a detailed clinical and laboratory approach is essential. First, a thorough bleeding history focusing on mucocutaneous bleeding symptoms such as easy bruising, epistaxis, menorrhagia, and prolonged bleeding after surgery or dental procedures is critical, as these are more characteristic of VWD compared to coagulation factor deficiencies which often present with deep tissue bleeding NICE NG121.

Next, initial laboratory screening should include a full blood count, prothrombin time (PT), activated partial thromboplastin time (aPTT), and importantly, specific assays for von Willebrand factor (VWF) antigen, VWF activity (ristocetin cofactor assay), and factor VIII levels. In VWD, VWF antigen and activity are typically reduced, often with a proportional decrease in factor VIII, whereas other bleeding disorders may show isolated factor deficiencies or normal VWF parameters NICE NG121 Baronciani & Peyvandi 2020.

Family history can guide suspicion but is not diagnostic alone; genetic testing may be considered in complex cases or when phenotypic assays are inconclusive Baronciani & Peyvandi 2020. Additionally, acquired von Willebrand syndrome should be excluded, especially in adults with new bleeding symptoms and underlying disorders Federici et al. 2004.

In cases where bleeding symptoms persist but standard tests are normal, a diagnosis of bleeding disorder of unknown cause (BDUC) may be considered after excluding VWD and other known disorders Mehic et al. 2024. This highlights the importance of comprehensive testing and specialist referral for complex cases.

In summary, differentiation relies on detailed bleeding history, targeted coagulation and VWF testing, and exclusion of other causes, supported by family history and specialist input when needed.