How should abnormal bruising be evaluated and managed?

Evaluation and Management of Abnormal Bruising

Abnormal bruising requires a systematic evaluation based on patient age, bruise location and pattern, bleeding history, and medication review, with initial laboratory screening (CBC with platelet count, PT, aPTT) followed by specialized testing for von Willebrand disease and platelet function disorders when indicated, while recognizing that normal screening tests do not exclude bleeding disorders. 1

Age-Specific Red Flags

Any bruising in infants under 6 months mandates immediate evaluation regardless of location or reported trauma, as bruising in pre-mobile infants is highly suspicious for abuse. 1 Non-ambulatory children with bruising warrant heightened concern and systematic evaluation for both medical causes and non-accidental trauma. 1

In children, bruising on ears, neck, trunk, buttocks, or genitals has higher specificity for abuse than bruising over bony prominences. 1 Patterned bruising is pathognomonic for inflicted injury. 1 However, the presence of a bleeding disorder does not rule out abuse, as both conditions can coexist. 2

Critical History and Physical Examination Elements

History Components

• Bleeding symptoms: Significant bleeding after circumcision, surgery, dental procedures, epistaxis, or umbilical stump bleeding suggest an underlying bleeding disorder. 2
• Medication review: NSAIDs, anticoagulants, antiplatelet agents, corticosteroids, and alternative therapies can cause or exacerbate bruising. 1
• Family history: Specific bleeding disorders or ethnicity with higher rates of certain conditions (e.g., Amish populations). 2
• Developmental capabilities: Assess whether bruising is consistent with the child's mobility and activity level. 2

Physical Examination

• Bruise location: Soft-tissue areas (thighs, upper arms, trunk) are more indicative of bleeding disorders than bruises over bony prominences from normal activity. 3
• Bruise pattern: Look for patterned injuries (slap marks, belt marks) that indicate inflicted trauma. 2
• Associated findings: Gingival bleeding, corkscrew hairs, poor wound healing suggest scurvy; porcelain-white papules with ecchymosis in anogenital area suggest lichen sclerosus. 4, 3

Initial Laboratory Evaluation

First-Line Screening Tests

• Complete blood count with platelet count: Identifies thrombocytopenia as a cause of bleeding. 1
• Prothrombin time (PT): Detects deficiencies in factors II, V, VII, X and vitamin K deficiency. 1
• Activated partial thromboplastin time (aPTT): Detects deficiencies in factors VIII, IX, XI, XII and the common pathway. 1
• Fibrinogen concentration: Detects fibrinogen defects. 3

Critical Limitations of Screening Tests

PT and aPTT do not detect von Willebrand disease, Factor XIII deficiency, or platelet function disorders—the most common causes of unexplained bruising with normal initial screening. 1 Von Willebrand disease affects approximately 1 in 1,000 individuals and is the most common inherited bleeding disorder. 5

Factor XIII deficiency produces substantial bruising despite completely normal PT/aPTT results and requires a specific Factor XIII activity assay for diagnosis. 5 The aPTT can be falsely prolonged with lupus anticoagulant or Factor XII deficiency, neither of which causes true bleeding. 3

Specialized Testing When Screening Tests Are Normal

Von Willebrand Disease Testing

When PT and aPTT are normal but clinical suspicion remains high, perform:

• VWF antigen level 3
• VWF ristocetin cofactor activity 3
• Factor VIII coagulant activity 3

Platelet Function Testing

Platelet function disorders show normal platelet counts but abnormal aggregation. 5 Diagnosis requires:

• Platelet aggregation studies (light transmission aggregometry) 3
• Flow cytometry to assess major platelet surface glycoproteins 3
• PFA-100 testing (note: results affected by certain medications) 2

Medical Conditions Causing Abnormal Bruising

Bleeding Disorders

• Von Willebrand disease: Mucocutaneous bleeding, easy bruising, normal PT/aPTT 5
• Hemophilia: Significant bruising even with mild deficiencies, particularly in males 3
• Factor XIII deficiency: Substantial bruising with normal PT/aPTT 5
• Immune thrombocytopenia (ITP): Transient, often self-resolving, low platelet count 3

Nutritional Deficiencies

• Vitamin K deficiency: Prolonged PT (and sometimes aPTT), especially in infants lacking prophylaxis 5
• Scurvy (vitamin C deficiency): Gingival bleeding, spontaneous bruising, corkscrew hairs, poor wound healing; risk factors include poor dietary intake, male gender, smoking, alcohol abuse 4, 5

Connective Tissue Disorders

• Ehlers-Danlos syndrome: Easy bruising from vascular fragility and connective tissue abnormalities; normal coagulation studies except possibly abnormal Hess test (capillary fragility test) 5, 6

Systemic Conditions

• Chronic liver disease/cirrhosis: Reduced synthesis of clotting factors causing spontaneous bruising 5
• Malignancies and infiltrative disorders: Thrombocytopenia or coagulation abnormalities 5
• Disseminated intravascular coagulation (DIC): Any type of bruising or bleeding, including severe intracranial hemorrhage 5

Age-Related Changes

• Senile purpura: Age-related thinning of blood vessels and skin in elderly patients 5

Specimen Handling and Testing Pitfalls

Coagulation tests are extremely sensitive to specimen handling and must be performed in experienced laboratories, as inappropriate handling commonly leads to false-positive results. 3 If blood product transfusions have been given, delay screening for bleeding disorders until elimination of transfused clotting elements. 3

Referral Indications

Hematology Referral

Refer when:

• Specialized testing (platelet function studies, VWD multimer analysis, Factor XIII assay) is needed 5
• Initial laboratory results are abnormal 1
• High clinical suspicion persists despite normal laboratory workup 1
• Complex cases require expert interpretation 1

Pediatric Abuse Consultation

Any suspected child abuse case should involve child abuse pediatrician consultation. 1 A skeletal survey is required for children under 24 months with bruising when there is witnessed or confessed abuse, domestic violence history, additional injuries on examination, patterned bruising, or when the child is under 6 months. 1

Management Algorithm

1. Assess age and mobility: Any bruising in infants <6 months or non-ambulatory children requires immediate evaluation. 1

2. Evaluate bruise characteristics: Location (soft tissue vs. bony prominence), pattern (patterned vs. non-patterned), and distribution. 3, 1

3. Obtain targeted history: Bleeding symptoms, medications (including OTC and supplements), family history, developmental capabilities. 2, 1

4. Perform initial laboratory screening: CBC with platelet count, PT, aPTT, fibrinogen. 1

5. If screening tests are normal but suspicion remains: Order VWD testing (VWF antigen, ristocetin cofactor, Factor VIII) and consider platelet function studies. 3

6. If screening tests are abnormal: Pursue specific factor assays, liver function tests, or DIC panel as indicated. 3

7. Consider non-hematologic causes: Scurvy, Ehlers-Danlos syndrome, medications, liver disease. 5, 4

8. In children with concerning features: Initiate child abuse evaluation simultaneously with medical workup—do not delay abuse investigation while pursuing medical causes. 1