Juvenile rheumatoid arthritis Health Article

Definition

Juvenile rheumatoid arthritis (JRA) is a general term for the most common types of arthritis in children. It is a long-term (chronic) disease resulting in joint pain and inflammation, which may lead to joint damage.

Alternative Names

Juvenile chronic polyarthritis; JRA; Still's disease; Juvenile idiopathic arthritis  

Causes, incidence, and risk factors

JRA occurs in 50-100 per 100,000 children in the United States. It usually occurs before age 16.

JRA is divided into several categories:

• Systemic JRA occurs in about 10% of cases. It involves joint pain, swelling, fevers, and rash. It is similar to adult Still's disease. The cause of this form of JRA is unknown.
• Polyarticular JRA occurs in about 40% of cases and involves multiple painful, swollen joints. The cause of this form of JRA is also unknown. Some children may have a positive rheumatoid factor and the condition may turn into rheumatoid arthritis.
• Pauciarticular JRA occurs in about 50% of cases and involves only a few joints. Some of these children, in particular boys, will be HLA-B27 positive. HLA-B27 is a substance called a gene marker that is associated with several autoimmune disorders.

Symptoms

Arthritis symptoms:

• Joint stiffness on arising in the morning
• Limited range of motion
• Slow rate of growth or uneven arm or leg growth
• Hot, swollen, painful joints
• A child may stop using an affected limb
• Back pain

Systemic JRA symptoms:

• Fever, usually high fevers every day
• Rash that comes and goes with the fever
• Swollen lymph nodes (glands)

JRA can also cause eye inflammation. These symptoms include:

• Red eyes
• Eye pain
• Photophobia (increased pain when looking at a light)
• Visual changes

Signs and tests

The physical examination shows swollen, warm, and tender joints that hurt to move. The child may have a rash. Other signs include an enlarged liver, enlarged spleen, or swollen lymph nodes.

Blood tests may include:

• CBC
• ESR (sedimentation rate)
• ANA
• RA factor
• HLA antigens for HLA B27

The doctor may need to tap a joint. This means that they will put a small needle into a joint that is swollen. This can help to find the cause of the arthritis. By removing fluid, the joint may feel better, too. Sometimes, the doctor will inject steroids into the joint to help decrease the swelling.

Other tests:

• X-ray of a joint
• X-ray of the chest
• ECG
• Eye exam by an ophthalmologist