Juvenile Rheumatoid Arthritis

Many people associate arthritis with the aging process. However, many young children – even babies – suffer from arthritis. Why? It’s a question researchers have been trying to answer for years.

The Mystery of Juvenile Arthritis
Juvenile arthritis affects nearly 300,000 children in the United States, according to the Arthritis Foundation. It is still unclear why children develop arthritis. Juvenile arthritis is different from adult arthritis in two ways: children with arthritis sometimes outgrow the illness, and it tends to be difficult to diagnose because the regular tests for arthritis are unreliable for children.

Polyarticular disease affects more than five joints (often many more), and can begin at any age. Some of these children have adult-type rheumatoid arthritis that begins at an earlier age than usual. “We usually think of arthritis as an ‘old person’ disease,” said Robert S. Katz, MD, a rheumatologist with Rheumatology Associates in Chicago. “But arthritis, especially rheumatoid arthritis, can happen at any age. Even a baby can have inflammation of a joint that could be rheumatoid arthritis.”

How Is Juvenile Rheumatoid Arthritis Different from Adult Rheumatoid Arthritis?
Although children can develop many of the same types of arthritis that affect adults, the most common in children is juvenile rheumatoid arthritis (JRA). According to the National Institute of Arthritis and Musculoskeletal and Skin Disease, the main difference between juvenile and adult rheumatoid arthritis is that many children with JRA outgrow the illness, while adults usually have lifelong symptoms. Studies estimate that by adulthood, JRA symptoms disappear in more than half of all affected children. Additionally, unlike rheumatoid arthritis in an adult, JRA may affect bone development as well as the child's growth.

Another difference between JRA and adult rheumatoid arthritis is the percentage of patients who test positive for the rheumatoid factor (RF). RF is an antibody found in the blood of many people with rheumatoid arthritis and is believed to play a role in tissue destruction associated with this disease. The Yale University School of Medicine Patient’s Guide to Medical Tests shows about 70 to 80 percent of adults with rheumatoid arthritis show signs of RF, but fewer than half of all children with rheumatoid arthritis are RF positive. Presence of the RF factor means there’s an increased chance that JRA will continue into adulthood.

What Causes Juvenile Arthritis?
The causes of juvenile arthritis are unknown, according to the American College of Rheumatology. “The cause of juvenile arthritis is thought to be associated with an autoimmune problem,” said Dr. Katz. Some genetic markers are more common in certain types of childhood arthritis or in children who develop particular complications from it. These conditions are not regarded as hereditary and rarely affect more than one family member.

What Are the Symptoms of Juvenile Rheumatoid Arthritis?
The most common symptom of JRA is persistent joint swelling, pain, and stiffness that are typically 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 may have a high fever and a light pink 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, internal organs including the heart and very rarely the lungs may be involved.

If your child has swelling of a joint over an extended period of time and pain is persistent, you’ll want to have your child see your family physician or the child’s pediatrician, Dr. Katz said. Your primary care physician may refer you to a specialist, such as a Pediatric Rheumatologist.

Eye inflammation is a potentially severe complication that sometimes occurs in children with pauciarticular JRA. Eye diseases often are not present until some time after a child first develops JRA.
Typically, there are periods when the symptoms of JRA can be in remission and times when symptoms flare up. JRA is different in each child—some may have just one or two flare ups and never have symptoms again, while others experience repeated flare ups or even have symptoms that never go away.

How Is Juvenile Rheumatoid Arthritis Diagnosed?
The American College of Rheumatology reports that juvenile arthritis may be difficult to diagnose because children often compensate well for loss of function and may not complain of pain. Observations of limping, stiffness when awakening, reluctance to use a limb or reduced activity level may be clues. Tests commonly “positive” in adult arthritis (rheumatoid factor in the blood or changes on x-rays) are often “negative” in childhood types. A number of other conditions can mimic juvenile arthritis, such as infections, childhood malignancies, musculoskeletal conditions or other less common rheumatic diseases, and further evaluation to exclude these may be necessary before a diagnosis is confirmed.

Who Treats Juvenile Rheumatoid Arthritis?
A pediatrician, family physician, or other primary care doctor frequently manages the treatment of a child with JRA, often with the help of other doctors. Depending on the patient's and parents' wishes and the severity of the disease, the team of doctors may include pediatric rheumatologists (doctors specializing in childhood arthritis), ophthalmologists (eye doctors), orthopaedic surgeons (bone specialists), and physiatrists (rehabilitation specialists), as well as physical and occupational therapists.

The main goals of treatment are to preserve a high level of physical and social functioning and maintain a good quality of life. To achieve these goals, doctors recommend treatments to reduce swelling; maintain full movement in the affected joints; relieve pain; and manage complications.

Several Types of Treatment
There are some very effective treatments now available for children with arthritis. The American College of Rheumatology reports that the choices of drugs for children are similar to those for adult arthritis and include nonsteroidal anti-inflammatory agents such as ibuprofen and slower acting agents such as methotrexate, sulfasalazine, and hydroxychloroquine for more severe cases. The doses must be adjusted for the size and gender of the child. Certain drugs such as steroids (cortisone) must be used with caution because of adverse effects on growth and other side effects. Some drugs for adults are not FDA-approved for use in children.

In addition to medications, physical therapy can be an important part of a child's treatment plan. Exercise can help to maintain muscle tone and preserve and recover the range of motion of the joints. A physical therapist can design an appropriate exercise program for a child with JRA. The physical therapist also may recommend using splints and other devices to keep joints growing evenly.

What Are Researchers Trying to Learn about Juvenile Rheumatoid Arthritis?
Scientists are investigating the possible causes of JRA. Researchers suspect that both genetic and environmental factors are involved in development of the disease. To help explore the role of genetics, the National Institute of Arthritis and Musculoskeletal and Skin Disease has established a research registry for families in which two or more siblings have JRA. The institute also funds a Multipurpose Arthritis and Musculoskeletal Diseases Center that specializes in research on pediatric rheumatic diseases, including JRA.

Research scientists are continuing to try to improve existing treatments and find new medicines that will work better with fewer side effects.