Pauciarticular juvenile rheumatoid arthritis (JRA), also known as oligoarthritis, is the most common and often the mildest type of JRA. Pauciarticular JRA most commonly affects the knees, ankles, fingers, toes, wrists, elbows, and hips.

Pauciarticular JRA affects four or fewer joints during the first 6 months of the disease. Symptoms tend to be limited to joint swelling and pain, but can also include uneven bone growth. This can lead to one leg being longer than the other. As it progresses, this type of JRA can develop into one of two conditions:

• Persistent oligoarthritis, maintaining a mild level of disease, with four or fewer joints affected
• Extended oligoarthritis, affecting five or more joints after the first 6 months of disease, with a course much like polyarticular JRA

Whole-body (systemic) symptoms (such as weakness, fatigue, and fever) are uncommon.

Children with pauciarticular JRA have a high risk of developing inflammatory eye disease, which can lead to blindness. Because eye damage can develop without causing symptoms, frequent eye exams are necessary.