Physical Child Abuse Differential Diagnoses

Diagnostic Considerations

Medical conditions may mimic some of the findings observed in physical abuse, and the differential diagnosis differs depending on the physical, laboratory, and radiologic findings observed. The differential diagnosis should be worked through carefully so that suspected physical abuse can be diagnosed confidently and caregivers are not inappropriately accused of abuse. It is important to recognize that child physical abuse is not a diagnosis of exclusion. Careful consideration and identification of an alternative diagnosis can avoid unnecessary investigations and interventions, as well as avoid delaying the evaluation and management of a previously unrecognized medical issue. Additionally, it is important to recognize that child physical abuse is sufficiently common that it may co-exist with other medical diagnoses. Drawing the distinction is important and may warrant consultation with subspecialty providers (See Consultations for more detail). 

Accidental versus inflicted trauma

For all injuries, once an underlying medical condition is excluded, the differential diagnosis is typically between accidental and inflicted injury. Semantics when discussing accidental versus abusive injury may suggest an interpretation of intent (“the caregiver did not mean, or intend, to cause the injury.”) Despite the language, it must remain clear that the determination of intent is outside of the scope of the medical evaluation and that the evaluation seeks to determine whether the injury is consistent with the history provided or whether it reflects an injury most likely caused by a caregiver, regardless of the underlying intent. Determination of accident versus abuse is best accomplished by pairing thoughtful, thorough medical evaluation with information gathered through a multidisciplinary investigation, often involving child protective services (CPS) and law enforcement agencies.

Falls are commonly reported accidents attributed to injuries, specifically short-distance falls (typically < 6 feet). Commonly resulting injuries include skull fractures with or without small underlying intracranial hemorrhage, particularly in infants. Significant life-threatening injury, clinical deterioration, and death is particularly rare in short falls. Long-bone fractures may also commonly result from short falls, typically involving older, ambulatory toddlers and young children (see Pathophysiology for more detail). 

Obstetric or birth-related trauma

Birth-related trauma is often raised as a concern, particularly when injuries are identified in young infants. 

CNS injury, including retinal hemorrhages, and fractures are common injuries that elicit birth-related concerns. 

Common birth-related fractures include clavicular fractures, which can result from routine deliveries, as well as long bone fractures and skull fractures, which are typically associated to particularly traumatic deliveries requiring instrumentation (ie, vacuum or forceps). Rib fractures have also been described, although typically associated with large neonates and particularly difficult deliveries. Pediatric radiology can be instrumental in determining whether features of healing support a birth-related timeframe of injury. 

Common birth-related cranial injuries include cephalohematomas and subgaleal hemorrhage. In deliveries requiring instrumentation, scalp lacerations may result. Delayed subaponeurotic fluid collection (DSFC) of infancy is an increasingly recognized finding thought to be associated with delivery instrumentation or particularly traumatic labor, although the exact pathophysiology remains unclear. DSFC typically becomes evident weeks to months after delivery, presents as a fluctuant, soft mass not bound by suture lines, and typically self-resolves without complication. These cranial findings typically do not pose a diagnostic dilemma. ^[30]  

Birth-related subdural hemorrhages are common and tend to be small, asymptomatic, and typically resolve without complications by 3 months of age. While some particularly traumatic births may result in more significant intracranial injury with neurological sequelae, these are likely to be identified in the neonatal period. ^[31] Nonetheless, a birth history should always be elicited when infants present with intracranial hemorrhage and review of birth records may help clarify important details. Retinal hemorrhages are also common birth-related findings typically resolving without complications by 4–6 weeks. ^[32]  Similarly, subconjunctival hemorrhages are common following birth, but typically resolve by 2–3 weeks of age. ^[33]  Subconjunctival hemorrhage outside of this period should elicit concern for trauma. ^[34]  

Bruises

For bruises, the differential diagnosis includes, but is not limited to the following:

• Anatomical variants:

  • Dermal melanocytosis (collection of melanocytes common to many races and ethnicities (ie, Black, Asian, Hispanic); may be present at birth or appear and evolve over the first year of a child's life); see images below
  • Hemangiomas (overgrowth of capillaries)

• Dermatological conditions:

  • Eczema
  • Phytophotodermatitis (cutaneous phototoxic cutaneous eruption resulting in erythematous areas and erosions due to sun exposure of skin that has psoralen residue)
  • Erythema multiforme (multi-shaped red lesions believed to be a sensitivity reaction)
  • Cold panniculitis 
• Bleeding disorders: 

  • Idiopathic thromobytopenia purpura (ITP)
  • Thrombocytopenia
  • Coagulation disorders (eg, hemophilia)
  • Malignancy (eg, leukemia)
• Collagen disorders: 

  • Ehlers-Danlos syndrome
  • Osteogenesis imperfecta (OI) type I
• Alternative traditional medicine practices:

  • Cupping (glass leaching) – involves a heated cup applied to the skin resulting in bruising due to associated negative pressure as the cup cools and generates a vacuum
  • Cao gio (coin rubbing) – involves vigorous rubbing of the back or chest with a coin edge until petechial or purpuric lesions appear
  • Gua sha (spooning) – similar to cao gio; involves scraping, typically with a porcelain spoon until petechial or ecchymotic lesions appear

Skeletal fractures

In addition to accidental trauma and birth-related trauma, the differential diagnosis for skeletal fractures includes, but is not limited to: 

• Normal anatomical variants of bone structure – may appear as concerning findings mimicking fractures on radiographs; discussion with pediatric radiology, as well as potential follow-up imaging, is important for clarification. Common variants include:

  • Physiological subperiosteal new bone formation – commonly seen in infants between 1 and 4 months; commonly bilateral and symmetric involving the femur, humerus, or tibia most often; appears as a smooth band of mineralized density along the bone shaft 
  • Nutrient vessel canals
  • Metaphyseal variants (eg, beak, step-off, spur)
• Bone mineralization disorders: 

  • Vitamin D deficient Rickets – laboratory results suggesting vitamin D deficiency or insufficiency has not been found to adequately account for bone fragility and fractures in the absence of radiological abnormalities including demineralization, widening of physes, and metaphyseal cupping
  • Disuse osteopenia – common in children with musculoskeletal disorders impeding normal ambulation, weight-bearing, and activity resulting in increased risk of skeletal injury with benign handling (ie, transfers, physical therapy)
  • Prematurity – while prematurity is not inherently a bone mineralization disorder, extremely premature infants are at risk of inadequate bone mineralization and fracture, particularly during their first year of life; additionally, neonatal intensive care management such prolonged total parenteral nutrition (TPN), diuretics, and proton-pump inhibitors further contribute to the risk of poor mineralization and subsequent fracture
• Collagen disorders: 

  • Osteogenesis imperfecta (OI) is frequently raised as a possibility in cases of unexplained fractures and possible physical abuse. Of note; OI is rare with an incidence of all types of OI estimated at 1 case in 20,000 live births
  • There are many types of OI. The following four types are the most commonly described:
    • OI Type I is characterized by mildly to moderately severe bone fragility with occasional fractures at birth, easy bruising, short stature, and blue sclera; may also be associated with a family history of hearing impairment. OI Type I is the most common form of OI, generally has autosomal dominant inheritance, and is responsible for 80% of OI patients. OI Type I may be confused with physical abuse, especially if all presenting injuries are skeletal. A thorough medical history and family history are essential, as well as Genetic consultation if concerns persists. 
    • OI Type II is a perinatal lethal form. Death typically occurs by age 1 month with multiple fractures at birth. This type of OI is generally readily distinguishable from child physical abuse.
    • OI Type III is rare, characterized by severe bone fragility and osteopenia, triangular facies, ligamentous laxity, skeletal deformity, and abnormal appearance of teeth. This type of OI is readily distinguishable from child physical abuse.
    • OI Type IV is typically characterized by mild-to-moderate bone fragility, osteopenia, wormian bones, birth fractures in approximately one third of cases, and normal sclerae. Type IV is the most difficult OI type to distinguish from child physical abuse because bones may appear normal when the first fracture develops.
  • Genetic consultation is appropriate to pursue a more detailed workup if concerns arise. ^[35]
• Other differentials to consider include: 

  • Infections (eg, congenital syphilis, osteomyelitis)
  • Nutritional deficiencies (eg, vitamin C deficiency)
  • Neoplasms (eg, bony metastasis)
  • Iatrogenic injury (eg, limb manipulation for medical procedures in young infants when considering CMLs, cardiopulmonary resuscitation when considering rib fractures)
  • Other medical conditions (eg, infantile cortical hyperostosis (Caffey's Disease), Menkes disease)

Burns

For burns, the differential diagnosis includes, but is not limited to the following dermatologic conditions: 

• Hypersensitivity reaction with blistering
• Friction blisters
• Impetigo - may appear circular and be confused with cigarette burns 
• Phytophotodermatitis - cutaneous phototoxic cutaneous eruption resulting in erythematous areas and erosions due to sun exposure of skin that has psoralen residue
• Dermatitis herpetiformis - immunobullous skin condition characterized by blisters that may erode

Additionally, as discussed for bruises, certain traditional medicine practices may mimic burn injuries. This should specifically be explored by the physician during history-gathering by asking about any medicinal practices or home-remedies. For the differential diagnosis of burns, these practices include: 

• Cupping - a heated cup is applied to the skin resulting in bruising due to associated negative pressure as the cup cools and generates a vacuum; heat may also generate burns
• Moxibustion - heating or burning of moxa plant at or very close to the skin

CNS injuries and abusive head trauma (AHT)

CNS injuries, particularly severe injuries, often present with altered mental status, as well as seizures and respiratory compromise. Prior to identification of the injury, the differential diagnosis elicits varios serious considerations such as meningitis, neurologic conditions that have seizures as a component, and ingestions.

Once intracranial hemorrhage, particularly subdural hemorrhage, is identified and concern for abusive head trauma is raised, the differential diagnosis for subdural hemorrhage warrants consideration. Similarly, depending on whether retinal hemorrhages are also identified, the differential diagnosis should also include the differential for retinal hemorrhages. 

For subdural hemorrhage, in addition to accidental trauma and birth-related trauma, the differential diagnosis includes, but is not limited to: 

• Coagulation disorders:

  • Hemophilias (Factor VIII deficiency, Factor IX deficiency)
  • Vitamin K deficiency – typically presents with intraparenchymal hemorrhage, but may present with any type of intracranial hemorrhage
• Vascular malformations, such as AVMs and arachnoid cysts
• Genetic and metabolic disorders:

  • Glutaric aciduria type I (associated with acute encephalopathy and subdural hemorrhage)
  • Menkes Disease – may present with developmental delay, seizures, and subdural hemorrhage in the context of cerebral vessel tortuosity and parenchymal abnormalities, as well as skeletal fractures, which may further raise concern for abuse at presentation
• Disordered CSF circulation: 

  • Benign enlargement of the extra-axial spaces (BESS; also known as benign extra-axial collections of infancy, benign expansion of the subarachnoid spaces): involves accumulation of CSF in the subarachnoid space leading to increased head circumference during the first 15-18 months of age. BESS is believed to be related to abnormal CSF resorption or circulation. As implied by the name, the clinical course is benign, without signs or symptoms of increased intracranial pressure or abnormal development. An increased risk of subdural hemorrhage is generally recognized, although the exact pathophysiology remains unclear. It is important to distinguish the subarachnoid from the subdural spaces, which is typically achievable via neuroimaging (ie, brain MRI). 
• Alternative medicine practices: 

  • caída de mollera ("fallen fontanelle") – has been described as part of Latin American traditional medicine where an infant is perceived to have a with a sunken, or "fallen," fontanelle in addition to perceived increased irritability, decreased appetite, and persistent crying. In an attempt to raise the perceived sunken fontanelle, the infant may be inverted, held upside down by the ankles, and tapped or shaken. Of note, while this practice has generated attention, the maneuvers employed are reportedly gentle and non-violent, as opposed to the violent shaking typically associated with AHT. ^[36]  

For retinal hemorrhages, in addition to accidental trauma and birth-related trauma, the differential diagnosis includes, but is not limited to:

• Vasculitis 
• Coagulopathies 
• Metabolic diseases (ie,  Glutaric aciduria type 1)
• Infection (ie, sepsis, endocarditis)
• Malignancy (ie,  leukemia)

Typically, the history and clinical findings will help clarify conflicting concerns. Of note, retinoschisis is typically not described in infants outside of traumatic mechanisms.