What labs and tests are recommended for a 69-year-old with easy bruising?

Evaluation of Easy Bruising in a 69-Year-Old Patient

For a 69-year-old patient with easy bruising, initial laboratory testing should include complete blood count (CBC), peripheral blood smear, prothrombin time (PT), activated partial thromboplastin time (aPTT), platelet function studies, and von Willebrand screening. 1

Initial Assessment

History Elements to Document

• Pattern and location of bruising
• Timing and triggers of bruising episodes
• Medication use, particularly:
  • Anticoagulants
  • Antiplatelet medications
  • NSAIDs
• Family history of bleeding disorders
• Previous bleeding episodes (surgery, dental procedures, childbirth)
• Other bleeding symptoms (epistaxis, gum bleeding, hematuria)

Physical Examination Focus

• Distribution and characteristics of bruises
• Presence of petechiae or purpura
• Mucosal bleeding (gums, nose)
• Joint examination for evidence of hemarthrosis
• Skin examination for signs of systemic disease

First-Line Laboratory Testing

1. Complete Blood Count (CBC)

   • Evaluates for thrombocytopenia and anemia
   • Assesses platelet count and morphology 2

2. Peripheral Blood Smear

   • Evaluates platelet size and morphology
   • Identifies abnormal cells suggesting malignancy 1

3. Coagulation Studies

   • PT/INR: Evaluates extrinsic pathway
   • aPTT: Evaluates intrinsic pathway 2, 1

4. Von Willebrand Disease Testing

   • Von Willebrand factor antigen
   • VWF activity
   • Factor VIII activity 2

5. Platelet Function Studies

   • Platelet aggregation testing (if available)
   • Consider PFA-100 (though limitations exist) 2

Interpretation of Results

Normal PT and aPTT

• Suggests platelet disorder or von Willebrand disease
• Von Willebrand disease is the most common inherited bleeding disorder 3
• Further specialized testing needed

Normal PT, Prolonged aPTT

• Indicates deficit in the intrinsic pathway
• Perform mixing study to differentiate between factor deficiency and inhibitor 3

Prolonged PT, Normal aPTT

• Consider vitamin K deficiency
• Perform vitamin K challenge test 3

Prolonged PT and aPTT

• Consider liver disease
• Evaluate for disseminated intravascular coagulation
• Check fibrinogen levels 3, 1

Special Considerations for Elderly Patients

• Age-related vascular fragility can cause easy bruising without underlying disorder
• Medication effects are common causes (anticoagulants, steroids)
• Consider senile purpura (actinic purpura) - purplish lesions on sun-exposed areas
• Higher risk of acquired bleeding disorders compared to younger patients

Common Pitfalls to Avoid

1. Inadequate medication review

   • Many medications can cause or worsen bruising
   • Document all prescription, over-the-counter, and herbal supplements

2. Overlooking acquired disorders

   • Liver disease, kidney disease, and malignancies can cause bleeding disorders
   • Consider these especially in elderly patients

3. Premature reassurance

   • Easy bruising may be the first sign of a serious underlying condition
   • Complete the recommended laboratory workup before concluding it's benign

4. Missing von Willebrand disease

   • Standard PT and aPTT may be normal
   • Specific testing for von Willebrand disease is essential 2

5. Failure to refer when appropriate

   • If initial testing is normal but clinical suspicion remains high
   • Refer to hematology for specialized testing 1

If initial testing does not reveal an etiology but clinical suspicion for a bleeding disorder remains high, referral to a hematologist is warranted for additional specialized testing and evaluation.