Which finding is most characteristic of enthesitis-related juvenile idiopathic arthritis?

Which finding is most characteristic of enthesitis-related juvenile idiopathic arthritis?

• A. Rash and fever
• B. Involvement of hips and sacroiliac joints with enthesitis
• C. Involvement of many joints
• D. Systemic symptoms

Answer: (B)

Enthesitis-related JIA is defined by inflammation at the entheses—the sites where tendons and ligaments attach to bone—combined with arthritis that commonly involves the lower limbs. The hallmark pattern is enthesitis with involvement of the hips and sacroiliac joints. This hip–SI joint pattern reflects a pediatric spondyloarthropathy and helps distinguish it from other JIA types. Rash, fever, and systemic symptoms point toward systemic JIA rather than this subtype, and widespread joint involvement without enthesitis suggests another form such as polyarticular JIA. So, hip and sacroiliac joint involvement with enthesitis is the most characteristic finding.

Enthesitis-related JIA is defined by inflammation at the entheses—the sites where tendons and ligaments attach to bone—combined with arthritis that commonly involves the lower limbs. The hallmark pattern is enthesitis with involvement of the hips and sacroiliac joints. This hip–SI joint pattern reflects a pediatric spondyloarthropathy and helps distinguish it from other JIA types. Rash, fever, and systemic symptoms point toward systemic JIA rather than this subtype, and widespread joint involvement without enthesitis suggests another form such as polyarticular JIA. So, hip and sacroiliac joint involvement with enthesitis is the most characteristic finding.