Juvenile rheumatoid arthritis (JRA) is a chronic disease of the joints. A chronic disease develops over a long period of time. In this case it starts before the age of 16 years old.

In JRA, the immune system attacks the tissue inside joints. This causes the joints to become inflamed. The process leads to pain and/or stiffness. The inflammation can cause long term damage to cartilage and bone. Cases may range from mild to severe. In some cases it can cause changes in growth and development.

There are five major types of JRA:

• Pauciarticular JRA— affects four or fewer joints
• Polyarticular JRA—affects five or more joints
• Systemic onset JRA (also called Still’s disease)—affects the entire body; least common type of JRA
• Enthesitis associated arthritis—occurs with inflammation of the tendon at the bone
• Psoriatic arthritis—associated with a skin disease called psoriasis

JRA is a potentially serious condition. It requires care from your doctor. The sooner JRA is treated, the better the outcome.

JRA is an autoimmune disease. This means it is the body's own immune system that causes the damage. The immune system problems may be caused by genetics and/or environment.

There are no clear risk factors for JRA. In general:

• Pauciarticular JRA
  • The first subtype typically affects girls under the age of 7
  • The other subtype typically affects boys over the age of 8
• Polyarticular JRA usually affects girls more often than boys
• Systemic onset JRA affects boys and girls equally
• For enthesitis associated arthritis, risk factors include a family history of:
  • Anterior uveitis with eye pain
  • Inflammatory back arthritis
  • Inflammatory bowel disease
• Psoriatic arthritis risk factor:
  • Arthritis and a positive family history of psoriasis in a first-degree relative

If your child has any of these, do not assume it is due to JRA. These symptoms may be caused by other, less serious health conditions. See your doctor if your child has any of these symptoms:

• Joint stiffness, especially in the morning or after periods of rest
• Pain, swelling, tenderness, or weakness in the joints
• Fever
• Weight loss
• Fatigue or irritability
• Eye inflammation
• Swollen lymph nodes
• Growth problems, such as:
  • Growth in affected joints may be too fast or too slow, causing one leg or arm to be longer than the other
  • Joints grow unevenly, off to one side
  • Overall growth may be slowed

Symptoms unique to the three major types of JRA are as follows:

Pauciarticular JRA:

• It usually involving large joints like knees, ankles, wrists, and elbows.
• Joints are generally affected in an asymmetrical pattern (if left side is affected, the joint on the right side is not).
• Children also often develop enthesitis. This is an inflammation at the spots where tendons and ligaments attach to the bones.
• May experience eye problems
• The first subtype is:
• • Associated with uveitis—a potentially serious eye condition
  • Often test positive for antinuclear antibodies (ANA)
• The second subtype involves the lower spine

Polyarticular JRA:

• Involves small joints of the fingers and hands, as well as weight-bearing joints (knees, hips, ankles, and feet).
• Joints are generally affected in a symmetrical pattern (if left side joint is affected, the same joint on the right side is as well).
• Anemia is low red blood cell count. It is a common symptom experienced by both subtypes.
• The first subtype is characterized by:
  • Presence of rheumatoid factor (RF) in the blood
  • A low-grade fever
  • Nodules (bumps on parts of body that receive a lot of pressure such as elbows)
• The second subtype is less severe. It only involves joint inflammation.

Systemic onset JRA:

• A high fever and chills, often accompanied by a rash on the thighs and chest. This appears off and on for weeks or months. They are the first signs of systemic onset JRA.
• Joint inflammation and pain are common.
• Heart, lungs, and surrounding tissues may become inflamed.
• Lymph nodes, liver, and/or spleen may become enlarged.
• Arthritis is in many joints.

• Enthesitis associated arthritis:
  • Tenderness over sacroiliac joints is common. This is the joint where the pelvis and spine meet.
  • Children will have a positive HLA-B27 antigen test.
  • Children will often have anterior uveitis. It is associated with eye pain, redness, or photophobia (problem with light).
• Psoriatic arthritis:
  • Finger or toe swelling or fingernail pitting. Pitting happens when fluids build up in the skin.

Often, there are remissions and flare-ups. During remissions the symptoms are better or disappear. During flare-ups symptoms become worse.

There is no one clear test for JRA. The doctor will work to rule out other diseases. Your doctor will ask about your child’s symptoms. Personal and family medical histories will be asked. The doctor will then perform a physical exam. Once your child's physician suspects JRA or makes this diagnosis, your child may be referred to a specialist. A pediatric rheumatologist focuses on diseases of the joints. Tests may include the following:

• Imaging techniques (such as x-rays)
• Laboratory tests on blood, urine, and/or joint fluid, to:
  • Rule out physical injury, bacterial or viral infection, other inflammatory diseases such as Lyme disease , inflammatory bowel disease , psoriasis, lupus , dermatomyositis , and some forms of cancer
  • Determine what subtype of JRA is present
• Ophthalmologic examinations—to detect inflammatory problems of various parts of the eye

Talk with your doctor about the best plan for your child. The goal is to preserve a high level of physical and social function and keep a good quality of life. The plan will work to control inflammation, relieve pain, prevent or control joint damage, and maximize joint function. Options include the following:

Several types of medication are available to treat JRA:

• Nonsteroidal anti-inflammatory drugs (NSAIDs)—such as ibuprofen , naproxen , diclofenac , or tolmetin
• Disease-modifying antirheumatic drugs (DMARDs)—such as methotrexate to slow the progression of the disease
• Corticosteroids—through IV (directly into the vein) or by mouth; for inflammation and swelling
• Immune response modulators—such as TNF inhibitors, for cases that do not respond as well

Exercises are performed to keep muscle strength. It also help to preserve and recover the range of motion of the joints. Normal daily activity, such as non-contact sports and recreational activities, are encouraged. Physical therapy may be needed to keep muscles strong and joints mobile. Children are also able to develop confidence in their physical abilities through such physical pursuits.

Splints and other devices are worn to maintain normal bone and joint growth. They can also help prevent flexion contractures (permanently bent joints).