Bilateral retinal hemorrhages: This is a common finding in infants with shaken baby syndrome or abusive head trauma, which is suspected given the history of multiple ED visits for unexplained fussiness and the current presentation of lethargy and minimal responsiveness to pain.

Grab marks and bruising on flanks: These are signs of physical abuse, which aligns with the suspicion of intentional head trauma. The presence of such marks indicates handling that could be consistent with shaking or other forms of abuse.
Papilledema: This can be a sign of increased intracranial pressure, which might be present in cases of head trauma, including abusive head trauma. It indicates swelling or pressure within the brain that could be due to the suspected trauma.

Bilateral macular edema: Although less common, macular edema could be associated with head trauma, including abusive head trauma. It's crucial to examine the retina thoroughly to not miss this potential sign of trauma.
Intracranial hemorrhage or other internal injuries: These are critical conditions that could be deadly if missed. Given the suspicion of intentional head trauma, it's essential to consider and rule out these conditions with appropriate imaging studies.

Accidental trauma with coincidental findings: While the history and presentation suggest intentional trauma, it's essential to consider the possibility, however rare, that the injuries could be accidental, especially if there's a plausible explanation for the head trauma and other findings.
Metabolic or genetic disorders mimicking trauma: Certain metabolic or genetic conditions could potentially mimic the signs of trauma, including lethargy and unexplained injuries. These would be rare but important to consider if the diagnosis of abusive head trauma is not clear-cut.