Sentinel bruising in a four-month-old infant
During a 4-month well-child visit, you note a 1.5 cm purple-brown bruise over the left cheekbone and two similar marks on the abdomen of infant Maya. She is not yet rolling and cannot cruise. Her father says she rolled off the couch this morning and hit the coffee table; the mother, who works nights, was asleep in another room. On exam Maya is alert, smiles, has no scalp swelling, a flat fontanelle, and no retinal hemorrhages visible on your limited exam. Her chart shows an emergency visit 6 weeks ago for a small bruise on the thigh recorded as accidental, with no further workup. The family recently moved and has no primary care elsewhere. The father is the only adult home during the day and is cooperative, asking whether he should put ice on it.
1. Which findings concern you, and what is your differential?
Read the worked answer
The central finding is any bruise in an infant who cannot roll, cruise, or pull to stand. Bruising in a nonmobile infant is a sentinel injury, associated with a meaningful risk of later serious or fatal injury, and a reported mechanism of rolling off a couch is not plausible for a 4-month-old who does not roll. Location adds concern: the cheek and abdomen are protected or torso areas, which the TEN-4-FACESp bruising rule flags (torso, ears, neck in children under 4 years; any bruise in an infant under 4 months). Two or more bruises plus a prior emergency visit for a thigh bruise recorded as accidental, with no workup, compounds the concern.
Differential:
- Inflicted injury.
- Accidental injury, but only if a mechanism fits the developmental stage.
- Bleeding disorder: obtain CBC with platelets, PT/PTT, and von Willebrand studies.
- Birthmarks or dermatologic conditions mistaken for bruises, such as Mongolian spots.
- Cultural practices such as coining or cupping, which produce patterned linear or circular marks rather than discrete oval bruises.
I would not label abuse at this point. I would gather data and protect the infant, because a missed sentinel injury is a potentially fatal error.
2. What are your immediate next steps in the clinic?
Read the worked answer
- Do not discharge until the evaluation and safety plan are complete. Keep Maya supervised in the clinic.
- Take the history separately from each caregiver: who was present, the exact sequence and timing, and what happened afterward. Record statements verbatim in quotation marks.
- Complete a full exam: undress her completely; measure and describe every mark by size, color, and location; examine the oral cavity and frenulum, scalp, palms, soles, and genitalia; use a body diagram; photograph per hospital policy.
- Order labs to exclude a bleeding disorder: CBC with platelets, PT/PTT, and von Willebrand antigen and activity.
- Order imaging: a skeletal survey for any child under 2 years with suspected abuse; head CT if there is altered mental status, vomiting, seizures, or scalp swelling, with consideration of MRI; arrange a dilated eye exam for retinal hemorrhage if there is any neurologic concern.
- Consult child abuse pediatrics and social work, and report to child protective services as a mandated reporter, plus law enforcement if state law requires.
- Continue ordinary care: feeding, immunizations, and any medical treatment. Reporting does not replace the therapeutic relationship. Arrange a follow-up plan with a named provider, since the family has no established pediatric home.
3. How do you talk with the parents, and how do you document?
Read the worked answer
Be honest and non-accusatory: 'I am worried about these bruises because Maya cannot roll yet, so a fall does not explain them. Our job is to keep her safe, so we are going to do some tests, and I am required by law to notify the child protection team. This does not mean I have decided what happened.' Do not interrogate the family, promise confidentiality, or imply that cooperation guarantees an outcome. Explain each test and the expected timing, acknowledge the father's cooperation, and offer social work support and an interpreter if needed.
Documentation should be objective:
- Measurements and descriptions of each mark, with a body diagram.
- Exact statements in quotation marks, labeled by speaker.
- Who was present during each conversation.
- That the reporting duty was explained to the family.
- The name of the child protection worker, the time of the report, and the instructions received.
Avoid conclusory words such as 'abuse' or 'inconsistent historian' in the chart; describe findings and statements and let the investigation reach conclusions. If the child is transferred, give a structured handoff to the receiving team and confirm that the report and follow-up are in place.