Pauciarticular JRA

Meaning "few joints," pauciarticular arthritis affects four or fewer joints. About 50 percent of children with JRA have this type. It often affects a particular joint only on one side of the body rather than on both sides at the same time.

Most Involved Joints:

Common: Large Joints

• Knees
• Ankles
• Elbows

Less Common: Small Joints

• Wrists
• Small finger or toe joints

Types
There are two different types of pauciarticular JRA.

One type usually affects girls under age seven. One-third of these children also develop eye inflammation (chronic iridocyclitis or uveitis). These children should be tested for antinuclear antibodies (ANA). ANA tells the rheumatologist and the ophthalmologist (eye doctor) whether your child has a higher risk of developing uveitis. A positive ANA test indicates a higher risk of developing eye inflammation.

WARNING: This eye condition is silent, meaning the damage might not be obvious to you or your child. Diagnosis and treatment requires proper monitoring by an eye doctor familiar with this complication of JRA. Another doctor may not find the changes in the eyes.

The second type of pauciarticular JRA usually affects boys over 8. The joints involved in this type are:

• Lower spine (sacroiliac joints)
• Hips
• Knees
• Ankles
• Tendons

The spots where tendons and ligaments attach to bones also may become inflamed (enthesitis).

Eye involvement in this type of pauciarticular JRA is usually acute instead of chronic. It can cause redness and pain in the eyes.

FACT: Children diagnosed with pauciarticular JRA and who have a positive ANA under age seven are at greatest risk of developing chronic uveitis. Their eyes should be checked every three months for several years.

NOTE: This type of pauciarticular JRA may be the first sign of another arthritis-related condition, such as spondyloarthropathies, a group of diseases affecting the spine, tendons and eyes. They may also be associated with a genetic factor in some people called HLA-B27.

Long-term Effects
Many children with JRA experience no long-term consequences. However, chronic damage can occur in the eyes. In fact, in some children, eye problems may be much more persistent than any joint damage.

On the other hand, some children develop chronic joint problems, including:

• Decreased range of motion or a joint
• Shortening or lengthening of a limb or digit.
• Damaged cartilage and/or enlargement of a joint.

In some children, the arthritis spreads to other joints. These children are said to have "extended pauciarticular JRA" which is similar to polyarticular JRA.