Physical abuse: bruising and sentinel injuries — formative SAQs

SAQ 1 — Bruise behind the ear in a 3-month-old (10 marks)

A 3-month-old infant is brought to the emergency department with coryza. On examination you notice a 1.5 cm bruise behind the left ear. The caregiver attributes it to the infant wriggling against the bouncy chair. The infant is not yet rolling over independently. [3] [2]

Questions

1. How do you interpret this bruise, and what is the clinical significance of its location and the infant's mobility? (4 marks) [3] [1]
2. Outline the investigations you would arrange and why. (3 marks) [4]
3. Describe the immediate safeguarding and disposition steps, including the role of mandatory reporting. (3 marks) [4] [2]

Model answer

Interpretation (4). Bruising is rare in infants who are not yet independently mobile; the foundational work on accidental bruising established that those who do not cruise rarely bruise. A bruise behind the ear is a TEN-4 region (ear) and in the TEN-4 FACES-L rule a single positive feature in a child under four triggers an abuse evaluation. The bouncy-chair mechanism is developmentally implausible for a 3-month-old who is not yet rolling. Treat this as a sentinel injury and a mandatory-reporting trigger. [3] [1] [5]

Investigations (3). A skeletal survey (dedicated films, not a babygram) because the infant is under two years, with a repeat at about two weeks to reveal occult rib and metaphyseal fractures. A coagulopathy panel (full blood examination and platelets, PT, aPTT, fibrinogen, von Willebrand panel) because bruising is the presenting feature, understanding that a normal result does not exclude abuse. Neuroimaging if any neurological sign or concern for abusive head trauma. [4] [11]

Safeguarding and disposition (3). Refer to the child-protection and social-work team and the designated doctor for child protection. Make the mandatory report under local statute; do not wait for certainty. Admit to a place of safety while the assessment is completed because the risk of recurrence after a sentinel injury is real regardless of how minor the bruise looks. Screen siblings and other young household contacts for occult injury. Document the mechanism verbatim and the multi-agency plan. [4] [2] [7]

SAQ 2 — Multiple bruises and a normal coagulation screen (10 marks)

A 14-month-old presents with bruises on the cheek, the sternal area, and the shin, plus a torn upper labial frenum. A coagulation screen performed at presentation returns normal. The family reports the child is "clumsy." [1] [9]

Questions

1. Apply the TEN-4 FACES-L rule to this child. Which features are positive? (3 marks) [1] [5]
2. How does the normal coagulation screen affect your assessment, and how should the bleeding-disorder differential be handled? (3 marks) [11] [4]
3. Outline your full safeguarding response and the pitfalls to avoid. (4 marks) [4] [2]

Model answer

TEN-4 FACES-L (3). The cheek is a FACES C site; the sternal area is a FACES S site; there are at least three bruised body regions and a patterned intra-oral injury (torn frenum). Multiple positive features are present, and the rule triggers on a single feature. The torn frenum in a young child is a high-specificity intra-oral finding. One positive feature is enough to mandate an abuse evaluation. [1] [5] [9]

Coagulation screen (3). A normal screen excludes some bleeding disorders but does not exclude rare ones and does not address the pattern. A bleeding disorder and abuse can coexist, so the evaluation is parallel, not sequential. Continue the full abuse work-up regardless of the normal result; extend haematology testing only if the pattern or history warrants. Do not close the case on a normal screen. [11] [4]

Safeguarding and pitfalls (4). Full undressed examination with body-map documentation and photography; skeletal survey under two years with repeat at about two weeks; neuroimaging if indicated; child-protection referral and mandatory report; admit to a place of safety; screen siblings; document mechanism verbatim. Pitfalls: accepting the "clumsy" explanation before testing developmental plausibility; relying on bruise colour to date injuries; treating the normal screen as proof of abuse; omitting the repeat skeletal survey; corridor confrontation. [4] [2] [7]