Differential Diagnosis for a 19-month-old with Arm Injury
- Single most likely diagnosis:
- Nursemaid's elbow (subluxation of the radial head): This is a common injury in young children, typically occurring when a child's arm is pulled while it is extended and the forearm is pronated, which can happen in the scenario described by the mother.
- Other Likely diagnoses:
- Fracture (e.g., forearm, humerus): Given the mechanism of injury (another child pulling the arm), a fracture is possible, especially if the force applied was significant.
- Soft tissue injury (e.g., bruising, sprain): The child could have sustained a soft tissue injury from the pull, leading to pain and favoring of the arm.
- Contusion: A direct blow to the arm could result in a contusion, which might cause the child to cry and favor the arm.
- Do Not Miss diagnoses:
- Non-accidental trauma: It's crucial to consider the possibility of child abuse, especially if the story provided does not match the severity of the injury or if there are inconsistencies in the history.
- Osteomyelitis or septic arthritis: Although less likely given the acute presentation after a specific incident, infections in the bone or joint can cause severe pain and must be considered, especially if the child shows signs of infection (fever, redness, swelling).
- Rare diagnoses:
- Pathologic fracture: If the child has an underlying bone condition (e.g., osteogenesis imperfecta), a fracture could occur with minimal trauma.
- Congenital conditions (e.g., congenital radial head dislocation): Some congenital conditions could predispose the child to specific types of injuries or could be uncovered during the evaluation of an acute injury.