Differential Diagnosis for a 2-year-old boy with left arm pain
- Single most likely diagnosis
- Subluxation of the radial head (nursemaid's elbow): This is the most likely diagnosis given the patient's age, the mechanism of injury (being pulled by the wrist), and the presentation of the arm hanging limp with the elbow slightly flexed. The patient's refusal to move the arm and pain upon straightening are also consistent with this diagnosis.
- Other Likely diagnoses
- Supracondylar fracture: Although less likely than subluxation of the radial head, a supracondylar fracture is a possible diagnosis given the mechanism of injury and the patient's symptoms. However, this type of fracture typically presents with more significant swelling and deformity.
- Torus fracture of the distal radius: A torus fracture is a possible diagnosis, but it is less likely given the mechanism of injury and the patient's age. Torus fractures are more common in older children and typically present with more localized pain and swelling.
- Do Not Miss diagnoses
- Anterior shoulder dislocation: Although unlikely in a 2-year-old, an anterior shoulder dislocation is a potentially serious injury that could be missed if not considered. It is essential to evaluate the shoulder joint, especially if the patient has significant pain or limited mobility.
- Epiphysial fracture of the distal radius and ulna: An epiphysial fracture is a rare but potentially serious injury that could be missed if not considered. It is essential to evaluate the growth plates and obtain imaging studies if necessary.
- Rare diagnoses
- Other rare fractures or injuries: Other rare fractures or injuries, such as a Monteggia fracture (fracture of the ulna with dislocation of the radial head), are possible but unlikely given the patient's age and presentation. These diagnoses should be considered if the patient's symptoms and imaging studies do not support the more likely diagnoses.