What is the likely cause of persistent bleeding in a young woman after wisdom teeth extraction, considering possibilities such as von Willebrand disease, immune thrombocytopenia, hemophilia B, hemophilia A, or disseminated intravascular coagulation?

Von Willebrand Disease is the Most Likely Diagnosis

In a young woman presenting with persistent bleeding after wisdom tooth extraction, von Willebrand disease (VWD) is the most likely diagnosis among the options provided. This represents the most common inherited bleeding disorder affecting approximately 1% of the general population, with characteristic mucocutaneous bleeding manifestations 1, 2.

Clinical Reasoning

Why Von Willebrand Disease is Most Likely

• VWD characteristically presents with mucosal bleeding, easy bruising, oral cavity bleeding, and bleeding after dental extraction 1
• Women are more likely to be diagnosed with VWD due to menorrhagia bringing them to medical attention, though the condition affects both sexes equally 1
• Bleeding after dental procedures is a hallmark manifestation of VWD, occurring because von Willebrand factor (VWF) is essential for platelet adhesion at sites of vascular injury 2
• Type 1 VWD (the most common subtype) may have normal or borderline screening tests, making it easily missed until a hemostatic challenge like tooth extraction occurs 2

Why Other Diagnoses are Less Likely

Hemophilia A and B are essentially excluded:

• Both hemophilias are X-linked recessive disorders affecting males almost exclusively; women would need to be homozygous (extremely rare) or have extreme lyonization 3, 4
• Hemophilias typically cause deep bleeding into muscles and joints (hemarthroses, hematomas), not primarily mucosal bleeding 4
• While mild hemophilia can present with post-extraction bleeding 3, this occurs in males

Immune thrombocytopenia (ITP) is possible but less likely:

• ITP would cause petechiae, purpura, and spontaneous mucosal bleeding beyond just the extraction site
• The bleeding pattern would be more generalized rather than localized to the surgical site

Disseminated intravascular coagulation (DIC) is highly unlikely:

• DIC is an acquired condition associated with sepsis, trauma, malignancy, or obstetric complications 5
• A previously healthy young woman undergoing routine dental extraction would not develop DIC without a precipitating acute illness
• DIC presents with multisystem bleeding and thrombosis, not isolated post-procedural bleeding

Diagnostic Approach

Order the following laboratory tests to confirm VWD:

• VWF antigen (VWF:Ag) - measures quantity of VWF 1, 2
• VWF ristocetin cofactor activity (VWF:RCo) or VWF activity (VWF:Act) - measures VWF function 1, 2
• Factor VIII coagulant activity - VWF is the carrier protein for Factor VIII 2
• VWF multimer analysis - distinguishes between VWD subtypes 1
• Blood type - Type O individuals have 25-30% lower VWF levels, which can confound diagnosis 2

Key diagnostic patterns:

• Type 1 VWD: Proportionally decreased VWF:Ag and VWF:RCo with normal multimer distribution 1
• Type 2 VWD: Disproportionately low VWF:RCo compared to VWF:Ag, abnormal multimers 1
• Type 3 VWD: Virtual absence of VWF and very low Factor VIII 1

Immediate Management of Post-Extraction Bleeding

Apply local hemostatic measures first:

• Direct pressure with gauze soaked in tranexamic acid
• Topical thrombin or fibrin glue application 5
• Suturing of the extraction site if not already done

If local measures fail and VWD is suspected:

• Desmopressin (DDAVP) 0.3 mcg/kg IV is first-line treatment for Type 1 VWD 6, 2
• DDAVP releases stored VWF from endothelial cells, increasing VWF and Factor VIII levels 3-6 fold within 30-90 minutes 6
• DDAVP is effective in most Type 1 VWD patients but contraindicated in Type 2B VWD (can cause thrombocytopenia) 7

If DDAVP is ineffective or contraindicated:

• Virally-inactivated plasma-derived VWF/Factor VIII concentrates are indicated 2
• These are necessary for Type 3 VWD and severe Type 2 variants 2

Adjunctive therapy:

• Tranexamic acid (antifibrinolytic) 1g IV or 10mg/kg orally three times daily reduces mucosal bleeding 1
• Avoid aspirin and NSAIDs which impair platelet function

Critical Pitfalls to Avoid

• Normal aPTT does not exclude VWD - aPTT may be normal in mild VWD, especially Type 1 3
• Do not rely on bleeding time alone - this test is poorly standardized and no longer recommended 2
• VWF levels fluctuate with stress, inflammation, and hormones - may need repeat testing if initial results are borderline 2
• Never give DDAVP to Type 2B VWD patients without confirming subtype - it can worsen thrombocytopenia 7