A 6-Year-Old Girl Is Brought to the Clinic for Evaluation

question 266

Multiple Choice

A 6-year-old girl is brought to the clinic for evaluation of knee pain.  The patient first had soreness in her right knee 4 days ago, after her first gymnastics class.  Her mother gave her acetaminophen and massaged her knee, but this did not help.  The patient also developed a limp over the past 2 days.  She has no chronic medical conditions and does not take daily medications.  Height is at the 50th percentile and weight is at the 75th percentile.  Temperature is 37.9 C (100.2 F) .  When walking, she limits weight-bearing on her right side.  When supine, the right hip is held flexed with the knee pointed laterally.  There is limited internal rotation and extension of the right hip.  The right knee has full range of motion and there is no tenderness on palpation around the knee.  Laboratory evaluation shows leukocyte count of 11,500/mm³ and C-reactive protein of 8 mg/L (normal: <10) .  Ultrasound of the hips shows small, bilateral effusions.  Which of the following is the most likely diagnosis in this patient?

• A)Juvenile idiopathic arthritis
• B)Osgood-Schlatter disease
• C)Septic arthritis
• D)Slipped capital femoral epiphysis
• E)Transient synovitis