What are the key clinical features to consider when diagnosing Juvenile Idiopathic Arthritis (JIA) in a child?

Key clinical features to consider when diagnosing Juvenile Idiopathic Arthritis (JIA) in a child include:

• Persistent joint swelling, redness, or stiffness, especially if the limp or joint symptoms are worse in the morning, indicating inflammatory joint disease.
• Limping or refusal to bear weight on the affected limb, often accompanied by painful limitation of joint movement.
• Joint pain and stiffness lasting for at least 6 weeks, which is a hallmark of JIA and helps differentiate it from transient causes of limp.
• Systemic features such as low-grade fever, fatigue, weight loss, or unexplained rash may be present, reflecting systemic inflammation.
• Absence of acute infection signs (e.g., high fever, severe pain waking the child at night) helps distinguish JIA from septic arthritis or malignancy, though specialist assessment is essential to exclude these.
• Multiple joint involvement or involvement of small joints can be a feature, but JIA may also present with monoarthritis.
• Symptoms persisting beyond transient synovitis duration, especially in children older than 3 years, as transient synovitis is rare under this age and septic arthritis is more common.

These clinical features should prompt urgent referral to a paediatric rheumatologist or appropriate specialist for further assessment and diagnosis, as early intervention improves outcomes ¹. Imaging such as ultrasound or MRI may assist in detecting synovitis and joint damage but is not routinely used in primary care [Dimitriou et al., 2017].

In summary, the diagnosis of JIA relies on identifying persistent inflammatory joint symptoms (swelling, stiffness, pain), systemic signs of inflammation, and excluding other serious causes of limp such as infection, malignancy, or trauma ¹. Recent literature supports the use of advanced imaging and highlights the heterogeneity of JIA presentations, reinforcing the need for specialist evaluation (Dimitriou et al., 2017).