What’s Your Diagnosis? Juvenile Idiopathic Arthritis

Welcome to this month’s What’s Your Diagnosis Challenge!

But before we begin, check to see if you got the previous case on Pediatric Apophysitis Management in the Emergency Department right.

Case Presentation: Management of Patients With Juvenile Idiopathic Arthritis in the Emergency Department 

An 18-month-old girl is brought into the ED for refusal to bear weight… 

• The mother says that the child has been limping for the past week. The limping is worse when the girl first wakes up and improves as the day progresses. Her mother denies constitutional symptoms. 
• On examination, you note bilateral swollen knees and ankles, with an inability to completely flex or extend at these joints. The girl’s vital signs and the rest of her physical examination are normal. Upon further questioning, the mother also tells you the girl has been eating less. 
• Laboratory work in the ED reveals mildly elevated inflammatory markers. Imaging with joint ultrasound reveals effusions and synovial hyperemia. 
• Should you be concerned for a joint infection? Should you consider other testing such as synovial fluid analysis or magnetic resonance imaging?

Case Conclusion

The girl was given naproxen and about 1 hour later, you noticed dramatic improvement in her joint pain and limping. She had improved range of motion of her bilateral knees and ankles and was walking without difficulty. Although her joints were still swollen, she was playful and much improved. You were suspicious that the patient likely had an inflammatory arthritis such as JIA. You were also aware that JIA is a chronic diagnosis and one of exclusion, and you consulted with orthopedics. Their team agreed with your assessment and thought that the toddler’s laboratory work and clinical appearance was not suggestive of underlying osteomyelitis or septic arthritis. You coordinated care with a pediatric rheumatologist for later in the week and provided the family with a prescription for naproxen.

USACS subscribers can log in or renew here.

Last Updated on May 7, 2025