What is the initial workup for a patient presenting with bruising?

Initial Workup for Bruising

The initial workup for a patient presenting with bruising should include a comprehensive clinical assessment followed by targeted laboratory testing, with complete blood count (CBC), peripheral blood smear, prothrombin time (PT), and activated partial thromboplastin time (aPTT) forming the core initial laboratory evaluation. 1, 2

Clinical Assessment

History

• Obtain detailed bleeding history using a structured approach such as the International Society on Thrombosis and Hemostasis bleeding assessment tool 1
• Document pattern, frequency, and severity of bruising 2
• Assess for associated symptoms (mucocutaneous bleeding suggests platelet disorders; hemarthroses or deep hematomas suggest coagulopathy) 1
• Review medication history, focusing on anticoagulants, antiplatelets, NSAIDs, and steroids 3
• Document family history of bleeding disorders (particularly important in children who may not have experienced major bleeding episodes) 1, 4

Physical Examination

• Document number, size, location, and pattern of bruises 5
• Evaluate for patterned bruises that may suggest non-accidental trauma, especially in vulnerable populations 5, 2
• Assess for additional injuries or signs of systemic disease 5
• In children, note that bruising in non-mobile infants or in unusual locations (ears, neck, torso, hands, feet) requires special consideration 5

Laboratory Evaluation

Initial Testing

• Complete blood count (CBC) with platelet count 3, 1, 2
• Peripheral blood smear examination 1, 2
• Prothrombin time (PT) and International Normalized Ratio (INR) 3, 2
• Activated partial thromboplastin time (aPTT) 3, 2
• Fibrinogen level 2

Interpretation of Initial Results

• Normal PT and aPTT with normal platelet count: Consider von Willebrand disease or platelet function disorders 3, 1
• Normal PT with prolonged aPTT: Suggests defect in the intrinsic pathway (hemophilia A or B, factor XI deficiency); perform mixing study 1, 2
• Prolonged PT with normal aPTT: Suggests defect in the extrinsic pathway; consider vitamin K deficiency 3, 2
• Prolonged PT and aPTT: Consider liver disease, DIC, or multiple factor deficiencies 3, 2
• Thrombocytopenia: Consider ITP, DIC, TTP, drug-induced causes, or malignancy 3, 6

Special Considerations

Children

• In children under 6 months with bruising, a skeletal survey and bleeding disorder workup are necessary regardless of bruise location 5
• For children 6-12 months, bruising in non-mobile infants requires thorough evaluation 5
• Consider non-accidental trauma in children with bruising in unusual locations or with patterned bruises 5

Trauma Patients

• In trauma patients with bruising and bleeding, immediate assessment of hemodynamic status using established grading systems is essential 5
• For trauma patients, include serum lactate and base deficit to estimate extent of bleeding and shock 5

Additional Testing Based on Initial Results

• If von Willebrand disease is suspected: von Willebrand factor antigen, ristocetin cofactor activity, and factor VIII level 3, 4
• For suspected platelet function disorders: platelet aggregation studies 3
• For suspected factor XIII deficiency (not detected by standard PT/aPTT): specific factor XIII assay 3
• For suspected liver disease: liver function tests 3

When to Refer to Hematology

• Abnormal initial laboratory workup suggesting a bleeding disorder 2
• High clinical suspicion despite normal initial laboratory results 2
• Severe or recurrent unexplained bruising 7
• Need for specialized testing (e.g., platelet function studies, von Willebrand panels) 4

Common Pitfalls to Avoid

• Relying on a single hematocrit measurement as an isolated marker for bleeding 5
• Failing to consider medication effects on bruising and bleeding 3
• Overlooking the possibility of non-accidental trauma in vulnerable populations 5, 2
• Assuming normal PT and aPTT rule out all bleeding disorders (they do not detect von Willebrand disease or factor XIII deficiency) 3, 4
• Delaying evaluation in patients with significant bruising or active bleeding 7