What is the appropriate work‑up for a patient presenting with easy bruising?

Work-Up for Easy Bruising

Begin with a targeted bleeding history and medication review, followed by initial laboratory screening with CBC with platelet count, peripheral blood smear, PT, and aPTT. 1

Structured Clinical History

Bleeding Symptom Assessment

• Ask specifically about significant bleeding after surgical or dental procedures (e.g., wisdom tooth extraction, tonsillectomy), as this is a red flag for an underlying hemostatic disorder 2
• Document epistaxis requiring medical intervention or cauterization, which suggests a bleeding disorder 2
• In females, assess for heavy menstrual bleeding defined by pad/tampon changes more frequently than every 2 hours, lasting >7 days, or causing anemia 2
• Inquire about joint hemorrhages, gastrointestinal bleeding, or bleeding from the umbilical stump in infancy 2

Medication and Supplement Review

• Document all medications that increase bleeding risk: anticoagulants, antiplatelet agents, NSAIDs, corticosteroids, and alternative therapies (ginkgo biloba, fish oil, garlic), as these affect both bleeding tendency and coagulation test results 2, 1

Family and Ethnic History

• Obtain family history of diagnosed bleeding disorders, particularly von Willebrand disease (the most common inherited bleeding disorder, affecting approximately 1 in 1,000 individuals) 2, 3
• Assess ethnicity associated with higher rates of certain bleeding disorders 2, 1

Trauma and Bruising Pattern Analysis

• Determine if the bruising pattern is explained by reported trauma 2, 1
• Bruises on soft-tissue areas (thighs, upper arms, trunk) are more suggestive of a bleeding disorder than bruises over bony prominences 2, 3
• Patterned bruising (linear or shape-specific marks) is more consistent with external trauma rather than a primary bleeding disorder 2

Systemic Disease Evaluation

• Assess for skin hyperextensibility or fragility suggesting Ehlers-Danlos syndrome 2
• Screen for nutritional deficiencies (vitamin C for scurvy, vitamin K) 2, 3
• Evaluate for constitutional symptoms (fever, unexplained weight loss, night sweats) that may signal malignancy or infiltrative disorders 2

Initial Laboratory Screening Panel

The core screening panel includes: 1

• Complete blood count (CBC) with platelet count 2, 1
• Peripheral blood smear to assess platelet morphology 3, 1
• Prothrombin time (PT) 2, 1
• Activated partial thromboplastin time (aPTT) 2, 1
• Add fibrinogen level if PT or aPTT are abnormal to detect fibrinogen defects 2, 1

Critical Diagnostic Pitfalls to Avoid

Limitations of Standard Coagulation Tests

• PT and aPTT do NOT reliably detect von Willebrand disease, Factor XIII deficiency, or platelet function disorders; normal results do not exclude these conditions 2, 3, 1
• Mild hemophilia (Factor VIII or IX deficiency) can present with significant bleeding despite a normal aPTT 2
• A normal platelet count does not exclude platelet function defects, which require specialized testing 3, 1

Specimen Handling

• Coagulation tests are very sensitive to specimen handling and should be performed in experienced laboratories, as inappropriate handling commonly leads to false-positive results 3
• aPTT can be falsely prolonged with lupus anticoagulant or Factor XII deficiency (which does not indicate a true bleeding disorder) 3

When to Pursue Additional Testing

If PT/aPTT Are Normal but Clinical Suspicion Remains High

• Perform VWD-specific testing: VWF antigen, VWF ristocetin cofactor activity, and Factor VIII coagulant activity 3
• Consider platelet function testing (e.g., PFA-100, light transmission aggregometry) for suspected platelet disorders 2, 3

If PT and/or aPTT Are Prolonged

• Evaluate for liver disease, vitamin K deficiency, or disseminated intravascular coagulation (DIC) 3
• In infants with prolonged PT, consider vitamin K deficiency testing, particularly if vitamin K was not administered at birth 2

Indications for Hematology Referral

Refer to hematology when: 2, 3

• Initial laboratory evaluation indicates a bleeding disorder
• High clinical suspicion remains despite normal laboratory workup
• Specialized testing is needed (VWD multimer analysis, Factor XIII assay, platelet aggregation studies)
• Complex cases require expert interpretation

Special Pediatric Considerations

In children <24 months with bruising, additional factors must be evaluated: 4

• Child's age and developmental capabilities to determine if bruising location is consistent with normal activity 2
• Location and pattern of bruising (buttocks, ears, genitals, or patterned bruising has higher specificity for abuse) 2
• Bone marrow examination should be considered if abnormal hemoglobin, WBC count or morphology, fever, bone/joint pain, family history of low platelets, skeletal abnormalities, non-petechial rash, lymphadenopathy, or hepatosplenomegaly are present 1