What could cause a bruise-like appearance without any injury?

Bruise-Like Appearance Without Injury: Differential Diagnosis and Evaluation

When bruising appears without reported trauma, the primary considerations are bleeding disorders, underlying medical conditions, medications/supplements, and in children—particularly those under 24 months or non-ambulatory—child abuse must be systematically evaluated. 1, 2

Age-Specific Red Flags

Pediatric Population (Critical Considerations)

• Any bruising in infants under 6 months requires immediate evaluation regardless of location or reported trauma history, as bruising in pre-mobile infants is highly suspicious for abuse 1, 2
• Bruising in non-ambulatory children (not yet cruising) warrants heightened concern 1
• Bruising on ears, neck, trunk, buttocks, or genitals has higher specificity for abuse than bruising on bony prominences 1
• Patterned bruising (hand marks, object imprints) is pathognomonic for inflicted injury 1

Adults

• Easy bruising complaints require systematic evaluation for bleeding disorders, medication effects, and systemic illness 2, 3, 4

Medical Causes to Evaluate

Bleeding Disorders

Von Willebrand disease and Factor XIII deficiency are NOT detected by standard PT/aPTT screening, making them critical considerations in unexplained bruising 1, 2

Other bleeding disorders include:

• Hemophilia (mild cases may have normal aPTT but still cause significant bleeding) 1
• Platelet disorders (thrombocytopenia, platelet dysfunction) 1, 2
• Fibrinogen defects (rare but detectable with fibrinogen level and thrombin time) 1, 2
• Acquired coagulation inhibitors (transient, can cause spontaneous bleeding) 5

Systemic Medical Conditions

• Ehlers-Danlos syndrome (connective tissue fragility) 1, 2
• Scurvy (vitamin C deficiency) 1
• Malignancy and infiltrative disorders 1, 2
• Liver disease (impaired coagulation factor synthesis) 4
• Vitamin K deficiency (particularly in infants not given vitamin K at birth) 2

Medication and Supplement Effects

• NSAIDs, anticoagulants, antiplatelet agents, and corticosteroids all increase bruising tendency 2
• Alternative therapies and supplements may affect coagulation 1
• These medications also interfere with platelet function testing interpretation 2

Systematic Evaluation Protocol

History Elements (Must Document)

• Bleeding symptoms: epistaxis, gingival bleeding, menorrhagia, bleeding after surgery/dental procedures, or joint hemorrhages 2, 4
• Family history of bleeding disorders or specific ethnic backgrounds with higher bleeding disorder prevalence 1, 2
• Complete medication review including over-the-counter drugs and supplements 1, 2
• Developmental stage in children to assess if bruise location matches mobility level 2

Physical Examination Focus

• Location and pattern of bruising (unusual locations suggest abuse or bleeding disorder) 1, 2
• Mucocutaneous bleeding suggests platelet dysfunction, while hemarthroses/deep hematomas suggest coagulopathy 4
• Signs of systemic illness (blue sclera in osteogenesis imperfecta, abnormal dentition, sparse kinky hair in Menkes disease) 1
• Petechiae at pressure points (clothing lines, infant seat fasteners) may indicate bleeding disorder 1

Initial Laboratory Testing

The screening panel should include: 2, 4

• Complete blood count with platelet count and peripheral blood smear
• Prothrombin time (PT)
• Activated partial thromboplastin time (aPTT)
• Fibrinogen level if PT or aPTT abnormal

Critical limitation: This standard panel misses von Willebrand disease and Factor XIII deficiency, which require specific testing 1, 2

When to Expand Testing

• High clinical suspicion despite normal screening tests warrants hematology referral 2
• Intracranial hemorrhage in non-mobile children requires bleeding disorder evaluation (unless witnessed trauma or other abuse findings present) 1
• Abnormal screening tests require specific factor assays and mixing studies 4

Pediatric-Specific Mandates

Skeletal survey is required for children under 24 months with bruising when: 1, 2

• Witnessed or confessed abuse history
• Domestic violence history
• Additional injuries on examination
• Patterned bruising present
• All infants under 6 months with any bruising

Common Pitfalls to Avoid

• Do not perform extensive bleeding disorder testing without clinical indication, as extreme rarity makes universal screening unreasonable 2
• Do not assume normal PT/aPTT excludes bleeding disorders—von Willebrand disease and Factor XIII deficiency require specific testing 1, 2
• Do not overlook medication effects on both bleeding tendency and test interpretation 2
• In children, do not accept implausible trauma explanations—mechanism must match injury type and severity 1
• Do not delay abuse evaluation while pursuing medical workup; both should occur simultaneously when abuse is suspected 1

Referral Indications

• Abnormal initial laboratory results indicating bleeding disorder 2
• High clinical suspicion with normal laboratory workup 2
• Need for specialized testing (platelet function analysis, specific factor assays) 2
• Complex cases requiring expert interpretation 2
• Any suspected child abuse case should involve child abuse pediatrician consultation 1