The Facts about Juvenile Rheumatoid Arthritis

Juvenile rheumatoid arthritis is arthritis that causes joint inflammation and stiffness for more than 6 weeks in a child of 16 years of age or less. Inflammation causes redness, swelling, warmth, and soreness in the joints, although many children with JRA do not complain of joint pain. Any joint can be affected and inflammation may limit the mobility of affected joints. One type of JRA can also affect the internal organs.

Doctors classify JRA into three types by the number of joints involved, the symptoms, and the presence or absence of certain proteins in the bloods. These classifications help the doctor determine how the disease will progress and whether the internal organs or skin are affected.

• Pauciarticular means that four or fewer joints are affected. Pauciarticular is the most common form of JRA; about half of all children with JRA have this type. Pauciarticular disease typically affects large joints, such as the knees. Girls under age 8 are most likely to develop this type of JRA.
  Eye disease affects about 20% to 30% of children with pauciarticular JRA. Regular examinations by an eye doctor are necessary to prevent serious eye problems. Some children with pauciarticular disease outgrow arthritis by adulthood, although eye problems can continue and joint symptoms may recur in some people.

• Polyarticular means that five or more joints are affected. About 30% of all children with JRA have polyarticular disease. The small joints, such as those in the hands and feet, are most commonly involved, but the disease may also affect large joints. Polyarticular JRA often is symmetrical; that is, it affects the same joint on both sides of the body.

• Systemic JRA is characterized by joint swelling, fever and a light skin rash. It may also affect internal organs such as the heart, liver, spleen, and lymph nodes. Doctors sometimes call it Still's disease. The systemic form affects 20% of all children with JRA. A small percentage of these children develop arthritis in many joints and can have severe arthritis that continues into adulthood.

Causes
JRA is an autoimmune disorder, meaning that the body mistakenly identifies some of its own cells and tissues as foreign. The immune system, which normally helps to fight off harmful foreign substances such as bacteria or viruses, begins to attack healthy cells and tissues. The result is inflammation - marked by redness, heat, pain, and swelling.

Doctors do not know why this happens in children who develop JRA, but scientists suspect that it is a two-step process. First, something in a child's genetic makeup gives them a tendency to develop JRA; then an environmental factor, such as a virus, triggers the development of JRA.

Signs and Symptoms
The most common symptom of all types of JRA is persistent joint swelling, pain, and stiffness that typically is worse in the morning or after a nap. The pain may limit movement of the affected joint although many children, especially younger ones, will not complain of pain. JRA commonly affects the knees and joints in the hands and feet. One of the earliest signs of JRA may be limping in the morning because of an affected knee.

Besides joint symptoms, children with systemic JRA have a high fever and a light skin rash. The rash and fever may appear and disappear very quickly. Systemic JRA also may cause the lymph nodes located in the neck and other parts of the body to swell. In some cases (less than half), internal organs including the heart and, very rarely, the lungs may be involved.

Eye inflammation is a potentially severe complication that sometimes occurs in children with pauciarticular JRA.

Typically, there are periods when the symptoms of JRA are better or disappear (called remissions) and times when symptoms are worse (flare-ups). JRA is different in each child - some might have just one or two flare-ups and never have symptoms again, while others experience many flare-ups or even have symptoms that never go away.

Some children with JRA may have growth problems. Depending on the severity of the disease and the joints involved, growth in affected joints may be too fast or too slow, causing one leg or arm to be longer than the other. Overall growth may also be slowed. Doctors are exploring the use of growth hormones to treat this problem. JRA also may cause joints to grow unevenly or to one side.

Diagnosis
Doctors usually suspect JRA, along with several other possible conditions, when they see children with persistent joint pain or swelling, unexplained skin rashes and fever, or swelling of lymph nodes or inflammation of internal organs. A diagnosis of JRA also is considered in children with an unexplained limp or excessive clumsiness.

No one test can be used to diagnose JRA. A doctor diagnoses JRA by carefully examining the patient and considering the patient's medical history, the results of laboratory tests, and X-rays that help rule out other conditions.

Treatment
Several types of medication are available to treat JRA, including:

• Nonsteroidal anti-inflammatory drugs (NSAIDs). Aspirin, ibuprofen, and naproxen or naproxen sodium are examples of NSAIDs. They often are the first type of medication used. Most doctors do not treat children with aspirin because of the possibility that it will cause bleeding problems, stomach upset, liver problems, or Reye's syndrome. But for some children, aspirin in the correct dose can control JRA symptoms effectively with few serious side effects.
• Disease-modifying anti-rheumatic drugs (DMARDs). If NSAIDs do not relieve symptoms of JRA, the doctor is likely to prescribe this type of medication. DMARDs slow the progression of JRA, but because they take weeks or months to relieve symptoms, they often are taken along with an NSAID.
• Corticosteroids. In children with very severe JRA, stronger medicines may be needed to stop serious symptoms. Corticosteroids like prednisone may be added to the treatment plan to control severe symptoms. Corticosteroids can interfere with a child's normal growth and can cause other side effects, such as a round face, weakened bones, and increased susceptibility to infections. Once the medication controls severe symptoms, the doctor may reduce the dose gradually and eventually stop it completely. Because it can be dangerous to stop taking corticosteroids suddenly, it is important that the patient carefully follow the doctor's instructions about how to take or reduce the dose.
• Biologic agents. Children with polyarticular JRA who have gotten little relief from other drugs may be given one of a class of drug treatments called "biologic agents." Etanercept (Enbrel), for example, blocks the actions of tumor necrosis factor, a naturally occurring protein in the body that helps cause inflammation.
• Physical therapy. Exercise is an important part of a child's treatment plan. It can help to maintain muscle tone and preserve and recover the range of motion of the joints. A physiatrist (rehabilitation specialist) or a physical therapist can design an appropriate exercise program for a person with JRA. The specialist also may recommend using splints and other devices to help maintain normal bone and joint growth.
• Complementary and alternative medicine. Many adults seek alternative ways of treating arthritis, such as special diets or supplements. Although these methods may not be harmful in and of themselves, no research to date shows that they help. Some people have tried acupuncture, in which thin needles are inserted at specific points in the body. Others have tried glucosamine and chondroitin sulfate, two natural substances found in and around cartilage cells, for osteoarthritis of the knee.

Although pain sometimes limits physical activity, exercise is important to reduce the symptoms of JRA and maintain function and range of motion of the joints. Most children with JRA can take part fully in physical activities and sports when their symptoms are under control. During a disease flare-up, however, the doctor may advise limiting certain activities depending on the joints involved. Once the flare-up is over, a child can start regular activities again.

Swimming is particularly useful because it uses many joints and muscles without putting weight on the joints. A doctor or physical therapist can recommend exercises and activities.

This article is based on information from the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

Each year, Medical College of Wisconsin physicians care for more than 180,000 patients, representing nearly 500,000 patient visits. Medical College physicians practice at Children's Hospital of Wisconsin, Froedtert Memorial Lutheran Hospital, the Milwaukee VA Medical Center, and many other hospitals and clinics in Milwaukee and southeastern Wisconsin.