What is the appropriate workup for a 3-year-old child presenting with daily bruising?

Workup for Daily Bruising in a 3-Year-Old

A 3-year-old with daily bruising requires immediate comprehensive evaluation including detailed history, thorough physical examination, and initial laboratory screening with CBC with platelet count, PT, aPTT, and von Willebrand studies, while simultaneously assessing for child abuse based on bruise characteristics and developmental stage. 1

Critical Initial Assessment

History Components

The evaluation must establish:

• Developmental mobility status (walking children have different bruising patterns than premobile children)
• Trauma history - specifically whether caregivers report any mechanism (falls, rough play, accidental hits)
• Family bleeding history - essential in young children who may not have experienced major bleeding episodes yet 1
• Birth history - vitamin K administration status, birth trauma
• "Classic" bleeding symptoms - bleeding after circumcision, umbilical stump bleeding, joint hemorrhage, excessive soft tissue bleeding 1
• Medication exposure that could affect coagulation

Physical Examination Focus

Document precisely:

• Number and size of bruises - children with bleeding disorders have more and larger bruises, especially if premobile 2
• Location patterns:
  • Bruises on ears, neck, cheeks, eyes, or genitalia are highly suspicious for abuse even in bleeding disorders 2
  • Patterned bruising suggests inflicted injury
  • Bruises in premobile infants at any location are concerning 3
• Other injuries - whip marks, burns, frenulum tears, fractures would indicate abuse 1
• Petechiae patterns - at clothing lines or pressure points may suggest bleeding disorder in context of normal handling 1

Laboratory Workup Algorithm

Initial Screening Panel

Order immediately 1:

• Complete blood count with platelet count (screens for ITP - the only transient bleeding disorder)
• Prothrombin time (PT)
• Activated partial thromboplastin time (aPTT)
• Fibrinogen level
• Von Willebrand studies (VWF antigen, VWF activity, Factor VIII) - critical as VWD is not reliably detected by PT/aPTT alone

This panel screens for conditions with prevalence >1 per 500,000, including ITP, most factor deficiencies, and von Willebrand disease 1.

Interpretation Framework

• Normal PT and aPTT: Suggests platelet disorder (most commonly von Willebrand disease) or mild hemophilia (which may not prolong aPTT) 1
• Prolonged aPTT, normal PT: Intrinsic pathway defect (factors VIII, IX, XI, XII)
• Prolonged PT, normal aPTT: Extrinsic pathway defect (factor VII) or vitamin K deficiency
• Both prolonged: Consider DIC, severe factor deficiencies, or liver disease 1

Critical Limitations

This screening does not detect:

• Factor XIII deficiency (can cause significant bleeding including intracranial hemorrhage)
• Mild platelet function disorders
• Fibrinolytic defects
• Defects of fibrinogen (though fibrinogen level helps)

Important caveat: aPTT can be falsely prolonged with lupus anticoagulant or factor XII deficiency (which doesn't cause bleeding). Coagulation tests require proper specimen handling in experienced laboratories 1.

Child Abuse Evaluation

When to Pursue Abuse Workup

Consider skeletal survey and further abuse evaluation when 3:

• Bruising in premobile infant (<6 months especially concerning)
• Bruises in high-risk locations (TEN-4 rule: Torso, Ears, Neck in children <4 years, plus any bruising in infants <4 months)
• Patterned bruising
• Multiple bruises without adequate explanation
• Inconsistent or changing history

Key Principle

A bleeding disorder does not exclude abuse 1. If laboratory testing suggests a bleeding disorder, follow-up examination after change in home setting can be valuable - bleeding disorders are permanent and don't improve with caregiver change (except ITP) 1.

Hematology Consultation

Refer to pediatric hematologist when 1:

• Initial screening suggests bleeding disorder
• High suspicion persists despite normal initial labs
• Need for expanded testing (platelet aggregation, factor XIII, specific rare disorders)
• Abnormal results require interpretation
• PFA-100 testing considered (though many centers have discontinued this due to limitations) 1

Special Considerations

Timing of Testing

If child received blood products or transfusions, delay bleeding disorder screening until transfused clotting elements are eliminated (factor half-lives range from 4-6 hours for Factor VII to 144-300 hours for Factor XIII) 1.

Vitamin K Deficiency

In infants, confirm vitamin K administration at birth. If deficient, presents with prolonged PT (possibly aPTT), and can cause severe bleeding including intracranial hemorrhage 1.

Clinical Decision Framework

For a 3-year-old with daily bruising:

1. Immediate red flags requiring urgent evaluation: Bruises on face/ears/neck/genitalia, premobile child with any bruising, patterned bruises, or concerning history
2. Obtain initial labs simultaneously with abuse assessment - don't delay either evaluation
3. Normal labs don't exclude bleeding disorder - mild disorders may not show on screening
4. Abnormal labs don't exclude abuse - both can coexist or bleeding disorder may be incidental finding

The priority is identifying life-threatening conditions (severe bleeding disorders, ongoing abuse) while avoiding false attribution of abuse when medical cause exists, or missing abuse when mild bleeding disorder is present.