What blood workup is recommended for a 22-year-old female presenting with bruising on the lower limb and epistaxis (nosebleed)?

Blood Workup for a 22-Year-Old Female with Bruising and Epistaxis

Order a complete blood count (CBC), prothrombin time (PT), activated partial thromboplastin time (aPTT), and von Willebrand disease (VWD) panel including VWF antigen, VWF ristocetin cofactor activity, and factor VIII levels as your initial laboratory evaluation. 1

Initial Hemostasis Screening Tests

The presence of both bruising on the lower limbs and epistaxis in a young female strongly suggests a possible bleeding disorder, particularly von Willebrand disease, which is the most common congenital bleeding disorder with a prevalence of approximately 1% and characteristically presents with mucocutaneous bleeding including epistaxis. 2, 3

First-Tier Laboratory Tests (Order Immediately)

• Complete blood count (CBC) to evaluate for thrombocytopenia or thrombocytosis 1
• Prothrombin time (PT) to assess the extrinsic coagulation pathway 1, 3
• Activated partial thromboplastin time (aPTT) to evaluate the intrinsic coagulation pathway 1, 3
• Peripheral blood smear to assess platelet morphology and identify qualitative platelet abnormalities 3

These initial tests do not evaluate for VWD specifically but can identify coagulation factor deficiencies or platelet count abnormalities that might explain the bleeding. 1

Von Willebrand Disease Testing (Order Concurrently)

Given the strong mucocutaneous bleeding history (epistaxis and bruising), order the VWD panel with your initial visit rather than waiting for screening test results. 1 This panel includes:

• VWF antigen (VWF:Ag) 1
• VWF ristocetin cofactor activity (VWF:RCo) 1
• Factor VIII coagulant activity (FVIII) 1

All three tests are necessary because the results not only establish the diagnosis but also suggest the type and severity of VWD if present. 1 If one or more results are abnormally low, or if the ratio of VWF:RCo to VWF:Ag is below 0.5-0.7, specialized VWD assays including multimer analysis should be considered. 1

Clinical Context and Physical Examination

Before ordering labs, document specific bleeding history details:

• Severity and frequency of epistaxis episodes 1
• Location and pattern of bruising (spontaneous vs. trauma-related) 3
• Family history of bleeding disorders, which is especially important in young patients who may not have experienced major bleeding episodes 3
• Medication review including NSAIDs, antiplatelet agents, or anticoagulants 3

Physical examination should identify ecchymoses, petechiae, hematomas, and other evidence of recent bleeding, while also looking for signs suggesting alternative diagnoses such as liver disease (jaundice, splenomegaly), joint hypermobility (Ehlers-Danlos syndrome), or telangiectasias (hereditary hemorrhagic telangiectasia). 1

Interpretation Algorithm

If PT and aPTT are normal: This indicates a platelet disorder, most commonly von Willebrand disease. 3 Proceed with VWD panel interpretation or consider platelet function testing if VWD panel is normal. 1

If PT is normal and aPTT is prolonged: This signals a deficit in the intrinsic pathway. Perform a mixing study to differentiate between factor deficiency and inhibitor. 3, 4

If PT is prolonged and aPTT is normal: Consider vitamin K deficiency or factor VII deficiency. 3

If both PT and aPTT are prolonged: Evaluate for liver disease, disseminated intravascular coagulation (DIC), or combined factor deficiencies. 3

Common Pitfalls to Avoid

• Do not rely solely on routine coagulation screening (PT, aPTT, platelet count) as these tests are insufficient to diagnose VWD, factor XIII deficiency, or platelet dysfunction. 2
• Do not delay VWD testing when mucocutaneous bleeding history is strong—order it with the initial visit rather than reflexively after abnormal screening tests. 1
• Do not overlook the bleeding time or platelet function analyzer (PFA-100), though these are not first-line tests and their use has decreased; some centers may add them to the workup. 1
• Do not assume normal screening tests exclude a bleeding disorder—if clinical suspicion remains high despite normal initial testing, refer to hematology for specialized evaluation. 3, 5

When to Refer to Hematology

Refer for hematology consultation if: 1, 3

• One or more VWD test results are abnormally low
• Screening tests are abnormal but etiology is unclear
• Strong personal or family history of bleeding despite normal initial workup
• Increasing number of positive responses to bleeding questions on clinical assessment

The prevalence of bleeding disorders in patients presenting with epistaxis is higher than in the general population (13% in one study), making thorough laboratory evaluation essential in this clinical scenario. 2