Physical Child Abuse Workup

The history and physical examination findings guide which laboratory and diagnostic imaging studies are necessary. Underlying medical conditions are often a consideration in the differential diagnosis of child physical abuse, and depending on the presenting finding(s), screening for potential physiological abnormalities is generally recommended (see DDx for more details).

Child physical abuse guidelines from the American Academy of Pediatrics (AAP) were updated in 2015 and reaffirmed in 2021. They include new information on the lasting effects of abuse and highlight risk factors for abuse and abusive injuries that are frequently overlooked. ^[1]

According to current guideline consensus, not all injuries require a comprehensive laboratory workup. Instead, testing should be driven by the history and physical exam, as well as the prevalence and known natural history of the disease being considered. 

The history and physical examination findings guide which laboratory and diagnostic imaging studies are necessary.

Bleeding concerns

If the patient presents with physical or radiological findings eliciting a differential diagnosis that includes a bleeding disorder, such as bruising or intracranial hemorrhage, a basic bleeding evaluation is a valuable screening tool and includes: 

• Complete blood count (ensure platelet count is included)
• Prothrombin time (PT)
• Activated partial thromboplastin time (aPTT)

Factor VIII, Factor IX, and von Willebrand assays are also recommended in initial screening for immobile children presenting with unexplained and concerning bruising. The prevalence of von Willebrand Disease, however, does not elicit significant concern when a patient presents with isolated intracranial hemorrhage, therefore von Willebrand assay is not recommended as initial screening in these cases. ^[37]

Consultation with pediatric hematology may be warranted to guide further laboratory workup and contextualize abnormal results.

Bone concerns

If a patient is found to have a skeletal injury (ie, fractures) eliciting a differential diagnosis that includes genetic bone disease or mineralization defect, the following screening levels are recommended:

• Serum calcium
• Serum magnesium
• Serum phosphorus
• Alkaline phosphatase levels, recognizing that levels may be elevated with fractures

Additionally, vitamin D 25-OH and intact PTH levels may also be appropriate. ^[38]

Interpretation of vitamin D levels in children is complex due to lack of robust evidence establishing normal values and thresholds below which bones would be clinically more susceptible to fracture. While vitamin D does have an important role in bone health and growth, the scientific evidence has failed to support correlation between low vitamin D levels and fractures in the absence of radiologically evident rachitic changes. 

Review of radiographs with a pediatric radiologist is ideal to evaluate bones for signs of poor growth, skeletal dysplasias, osteopenia, and abnormal healing. 

Abnormal lab results may warrant contextualization and clarification from a pediatric endocrinologist.

Similarly, genetics consultation may be warranted, particularly when considering genetic testing for conditions such as osteogenesis imperfecta. Genetic consultation is also paramount for the interpretation of genetic testing results and to guide subsequent testing, if warranted. ^[35]

Occult abdominal trauma screening

Screening for abdominal injury is currently recommended in young children who present with injuries concerning for physical abuse, even in the absence of clear external evidence of abdominal injury or symptoms such as tenderness, distention, or abdominal bruising. ^{[39, 40]} Note the image below. 

Screening recommendations for occult abdominal trauma include:

• aspartate aminotransferase (AST) 
• alanine aminotransferase (ALT) 

An AST or ALT value greater than 80 IU/L has been proposed as a cutoff to guide subsequent imaging (see Imaging for more details). 

Prior recommendations have also suggested screening with amylase and lipase levels for pancreatic injury, urine analysis for red blood cells to evaluate for urinary tract injury, and stool guaiac for intestinal injury. However, these markers are no longer supported for routine screening given insufficient evidence. Instead, obtaining these markers should be guided by clinical findings.  

Toxicology screening

Toxicology screening is indicated if the clinical situation suggests a possible ingestion as the cause of the findings on examination. For example, unexplained altered mental status, particularly in young, otherwise healthy children in the absence of intracranial injury, should elicit concern for occult intoxication. 

Often, a child presents from a household where drug use or production is suspected or confirmed. While there is no clear evidence-based recommendations, it is encouraged that treating physicians guide their evaluation by clinically relevant findings rather than by forensic purposes.

Urine and serum toxicology screening with corresponding confirmatory testing is the preferred method of testing.

While hair testing is often brought up as a forensically relevant method to assess drug exposure, it is not clinically useful and is not recommended in the acute setting. ^[41]

Consultation with medical toxicology may be warranted for interpretation of findings and to guide subsequent testing.

Other laboratory testing

Child physical abuse is a form of trauma and its evaluation should reflect as such. While the above recommendations stem from specific injury-guided research, the comprehensive evaluation of a child with suspected child physical abuse should reflect the child’s underlying injury. 

For example, blunt chest trauma may elicit concern for cardiac injury and may prompt troponin levels, while significant muscle injury may prompt creatine kinase levels. Testing, nonetheless, should be performed in accordance to standard of care and, whenever available, evidence-based guidelines. 

In addition to a comprehensive history and physical exam, radiological imaging is an important part of the evaluation of child physical abuse. Many injuries (such as fractures, brain trauma, and abdominal trauma) are not necessarily associated with external signs of trauma. Additionally, while many injuries may in fact be externally evident, clinically vague or silent injuries can often be identified with appropriate imaging and clinicians should maintain a high index of suspicion. This section will discuss indications of common imaging modalities involved in the evaluation of child physical abuse as per the American Academy of Pediatrics (AAP) and American College of Radiology (ACR) guidelines ^[42] (see Imaging in Child Abuse for additional details).

Skeletal survey

A skeletal survey is indicated in children ≤ 24 months old with concerns for child physical abuse; concerns may be prompted by injuries recognized on prior imaging such as another skeletal injury, brain injury, solid organ or hollow viscus injury, or by external signs of trauma (ie, mucocutaneous injury). A skeletal survey helps the physician assess for occult, clinically subtle, acute or healing fractures. ^[42]  It is important to differentiate between a skeletal survey and a babygram; a babygram is a non-targeted single radiograph of an infant's entire body and is not appropriate for occult injury screening purposes. 

When a skeletal injury concerning for physical abuse is identified or when the initial skeletal survey is negative, but significant concern for abusive injury persists, a follow-up skeletal survey is typically recommended 10–14 days after the initial skeletal survey is performed in children ≤ 24 months old; exclusion of the pelvis, spine, and skull films – if initially negative – can be considered to decrease radiation exposure. ^[43] A retrospective study of children assessed with skeletal surveys to evaluate for missed physical abuse and unsuspected fractures found that about 11% of the survey results were positive for a previously unsuspected fracture. The skeletal survey results directly influenced the diagnosis of abuse in 50% of the children with positive skeletal survey results. ^[44]

In children between 24 and 36 months old, the yield of the skeletal survey is believed to be lower than in those ≤ 24 months; however, the exact yield is unclear. A skeletal survey can be considered in this age group, particularly for children with significant injuries who are unable to localize pain. 

Children > 36 months are typically best imaged by way of focused radiographs of areas of concern rather than a complete skeletal survey. Areas of concern should be determined by the physical exam.

For close contacts of children ≤ 24 months with findings concerning for child physical abuse, the clinician should also consider they undergo a skeletal survey given a well-recognized increased risk of abuse in close contacts sharing an abusive care environment. ^[45]

Recommendations have supported the use of bone scintigraphy (ie, radionucleotide bone scan) as an adjunct to the skeletal survey, particularly when rib fractures or subtle long bone fractures are unclear on initial skeletal survey and concern for physical abuse is significant. However, concerns persist regarding this modality’s availability, the need for venipuncture and sedation, and challenges to the interpretation of other bony findings detected as the scan may remain active for up to a year. 

Neuroimaging

Because cranial and intracranial injury are common findings prompting concern for inflicted injury in young children and infants, neuroimaging modalities are important in the evaluation of child physical abuse. The modalities most commonly used are the non-contrast head CT and brain MRI. 

Non-contrast head CT is the imaging modality of choice in children presenting with signs and symptoms concerning for intracranial injury (ie, seizures, altered mental status, vomiting without associated diarrhea, apnea, etc.). If an intracranial injury is identified on head CT, brain MRI can be a valuable adjunct to further define the injury, identify features suggesting injury chronicity, and detect diffusion-weighted imaging abnormalities and evolving parenchymal injury. Additionally, the brain MRI may provide prognostic information that may help guide follow-up management. ^[42]  

Unenhanced brain MRI with diffusion-weighted imaging (DWI), gradient echo sequence, or susceptibility-weighted imaging (SWI) is sensitive for the detection of parenchymal injury, signs of torn or thrombosed bridging veins, and small amounts of extra-axial hemorrhage. 

The brain MRI, in cases concerning for abusive head trauma, is generally performed in stable patients 72–120 hours following a suspected acute injury (ie, patients with acute neurological alteration or deterioration) to best detect DWI abnormalities or cytotoxic edema. 

Evidence supports that spinal injuries, particularly ligamentous injury and spinal subdural hemorrhage, are relatively common findings in abusive head trauma. While cervical MRI is typically recommended in conjunction with brain MRI, the utility and feasibility of routine whole-spine MRI continues to be debated. 

Of note, studies have increasingly supported the use of fast MRI sequences as an accurate and feasible alternative to non-contrast head CT, though this is not yet readily available in all institutions and has not yet replaced the head CT as the initial imaging modality of choice. ^[46]

In infants < 6 months old presenting with injuries concerning for child physical abuse (ie,mucocutaneous injuries, skeletal injuries, etc.), consideration of non-contrast head CT to screen for occult intracranial injury is generally recommended. ^[47] In infants between 6 and 12 months, recommendations vary. In general, non-contrast head CT should be considered, particularly if the infant presents with neurological concerns (ie,irritability, vomiting without diarrhea, seizures, poor feeding, etc.) or cutaneous injuries on exam. ^[48]  

Evidence supporting close contact screening for occult intracranial injury is limited. However, the risk of concomitant abuse has been well established. ^[45]  There are increased calls for standardization of close contact screening with neuroimaging, especially when an index child presents with findings concerning for abusive head trauma and contacts are infants. ^[49]  

Abdominal and thoracic imaging

Abdominal CT with IV contrast is recommended when there are concerns for abdominal solid organ or hollow viscus injury. Signs that may prompt imaging include abdominal wall bruising, abdominal tenderness or pain, or abdominal distention.

Currently a liver transaminase value (ALT or AST) > 80 IU/L in children presenting with injuries concerning for child physical abuse has been proposed as a cutoff prompting consideration of abdominal CT with IV contrast in the absence of abdominal signs. ^[50]  Research to refine this cutoff value is ongoing. 

Chest CT is not routinely recommended for occult injury screening, unless clinically indicated. Chest CT may be helpful to clarify thoracic injury, including rib fractures. The risk of radiation versus the benefit of injury clarification must be weighed when chest CT is used for screening purposes or as an adjunct to the skeletal survey. 

Ophthalmologic exam (dilated fundus examination)

One particular procedure important to consider when concerns for abusive head trauma arise is a dilated fundus examination (DFE). ^[51]  

This diagnostic procedure uses mydriatic (dilating) eye drops to dilate the pupil and allow visualization of the fundus, including the retina, optic disc, macula, blood vessels, and other features with the use of an indirect ophthalmoscope. Fundus photography is often an adjunct to the DFE and should be encouraged whenever possible to allow for peer discussion and accurate documentation. 

Generally, recommendations for DFE in the evaluation of child physical abuse are driven by the identification of intracranial hemorrhage, particularly subdural hemorrhage, which have in turn elicited concern for abusive head trauma. The DFE is best to complete within the first 72 hours of presentation, but preferable within the first 24 hours, to best characterize retinal findings. While some retinal injuries may persist beyond 72 hours, the full extent of the presenting injuries may rapidly evolve and resolve. ^[52]  

The DFE should be performed by pediatric ophthalmology whenever possible (see Consultations). Concerns for acute neurological deterioration may require close monitoring of pupillary response, in turn delaying DFE. While less preferable, DFE after 72 hours may still be useful rather than deferring the examination altogether, although caution should be exerted when interpretating the findings. 

Close multidisciplinary coordination between involved subspecialties (ie, child abuse pediatrics, neurosurgery, critical care, and pediatric ophthalmology) is typically warranted (see Consultations for more detail).