Differential Diagnosis for Knee Pain in a 6-year-old Girl
- Single most likely diagnosis
- E. Transient synovitis: This condition is the most likely diagnosis given the patient's presentation of acute hip pain, limited weight-bearing, and ultrasound findings of small, bilateral hip effusions. The patient's symptoms and laboratory results, such as a mildly elevated leukocyte count and C-reactive protein within normal limits, also support this diagnosis. Transient synovitis is a common cause of hip pain in children and often follows a viral illness or trauma.
- Other Likely diagnoses
- A. Juvenile idiopathic arthritis: Although the patient's symptoms could be consistent with juvenile idiopathic arthritis, the lack of significant laboratory abnormalities and the absence of systemic symptoms make this diagnosis less likely. However, it remains a possibility and should be considered if the patient's symptoms persist or worsen.
- B. Osgood-Schlatter disease: This condition typically presents with knee pain and swelling, particularly in the tibial tubercle area. However, the patient's knee has full range of motion and no tenderness on palpation, making this diagnosis less likely.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- C. Septic arthritis: Although the patient's laboratory results do not strongly suggest septic arthritis, this diagnosis is a medical emergency that requires prompt attention. The presence of hip pain, limited mobility, and effusion on ultrasound necessitates consideration of septic arthritis, even if it is less likely.
- Rare diagnoses
- D. Slipped capital femoral epiphysis: This condition typically occurs in older children and adolescents, particularly those who are overweight. The patient's age and weight percentile make this diagnosis less likely, but it should be considered if the patient's symptoms worsen or if there are any changes in the hip examination.