Which Juvenile Idiopathic Arthritis subtype is defined by four or fewer joints and is commonly associated with uveitis?

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

Answer: (B)

In juvenile idiopathic arthritis, grouping by how many joints are affected helps identify the pattern. Four or fewer joints defines the oligoarticular pattern, which is the most common JIA in young children. This subtype is strongly associated with uveitis, especially chronic anterior uveitis, and many patients are ANA positive. Because the eye inflammation can be asymptomatic, regular eye exams are important for early detection and management. Clinically, oligoarticular JIA typically involves large joints such as the knees, ankles, or wrists, often affecting a few joints early on.

Other subtypes don’t fit this pattern: systemic JIA presents with fever and systemic features; polyarticular JIA involves five or more joints; psoriatic JIA includes psoriasis features or enthesitis.