Which JIA subtype involves more than five joints?

• A. Systemic JIA
• B. Oligoarticular JIA
• C. Psoriatic JIA
• D. Polyarticular JIA

Answer: (D)

Many joints being involved is the hallmark of polyarticular JIA. This subtype is defined by arthritis in five or more joints, often appearing in a symmetric pattern and commonly affecting both small joints (like those of the hands and feet) and larger joints. This contrasts with oligoarticular JIA, which involves four or fewer joints, and systemic JIA, where systemic features such as fever and rash are prominent along with arthritis. Psoriatic JIA is distinguished by psoriasis-related signs (like skin plaques or nail changes) and may not always correlate with a specific joint-count category. So when the question asks for involvement of more than five joints, the best fit is polyarticular JIA, which encompasses five or more joints.