What further testing is indicated for a 29-year-old female with easy bruising and normal coagulation studies, including normal Partial Thromboplastin Time (PTT), Complete Blood Count (CBC), and International Normalized Ratio (INR)?

Further Testing for Easy Bruising with Normal Coagulation Studies

For a 29-year-old female with easy bruising and normal PTT, CBC, and INR, von Willebrand disease testing should be performed as the next step, including von Willebrand factor antigen (VWF:Ag), von Willebrand factor ristocetin cofactor activity (VWF:RCo), and factor VIII coagulant activity (FVIII). 1

Rationale for Testing

Normal coagulation studies (PTT, CBC, INR) do not exclude common bleeding disorders such as von Willebrand disease (VWD), which is:

• The most common inherited bleeding disorder
• Often presents with normal PT/PTT/INR
• More common in women due to hormonal influences and menstrual bleeding

Recommended Testing Algorithm

1. First-line specialized testing:

   • Von Willebrand factor antigen (VWF:Ag)
   • Von Willebrand factor ristocetin cofactor activity (VWF:RCo)
   • Factor VIII coagulant activity (FVIII)

2. If initial VWD testing is normal, consider:

   • Platelet function testing, including light transmission aggregometry with multiple agonists 1
   • Testing for platelet granule release
   • Flow cytometry for platelet surface glycoproteins

3. If high clinical suspicion persists despite normal testing:

   • Hematology consultation is recommended 1, 2
   • Up to 60-70% of patients with mild-moderate bleeding symptoms may have a bleeding disorder of unknown cause even after initial testing 1

Important Considerations

• Patient factors affecting test results:

  • Stress, exercise, inflammation, pregnancy, or estrogen use can elevate VWF and FVIII levels, potentially masking disorders 1
  • ABO blood type influences VWF levels (Type O individuals have ~30% lower levels)
  • Medications should be reviewed (discontinue those affecting platelet function 7-10 days before testing)

• Classification insights:

  • Easy bruising syndrome can be categorized into two types 3:
    • Type I: Normal to supranormal platelet function
    • Type II: Abnormal platelet function with impaired aggregation

• Limitations of screening tests:

  • Bleeding time and PFA-100 tests have conflicting data regarding sensitivity and specificity and are not recommended as routine screening tests 1
  • Relying solely on PT/PTT/INR to exclude bleeding disorders can lead to missed diagnoses 1, 2

When to Refer

• Refer to a hematologist when:
  • Initial VWD testing is abnormal
  • High clinical suspicion remains despite normal initial testing
  • Specialized testing interpretation is needed 1, 2

This approach ensures thorough evaluation of the most likely causes of easy bruising in a young woman with normal basic coagulation studies, with von Willebrand disease being the most important condition to rule out first.