Definition and Overview
Juvenile rheumatoid arthritis (JRA) is an autoimmune form of arthritis that affects children. Also known as juvenile idiopathic arthritis, JRA is an inflammatory condition of the joints, most commonly affecting the knee and the distal joints of the upper and lower extremities. It is diagnosed in children who are younger than 16 years old, with symptoms lasting for a minimum of 6 weeks. Juvenile rheumatoid arthritis can occur at any time during childhood, but commonly afflicts children from 1 up to 3 years of age. It is more commonly seen in females and Caucasians. More than 200,000 children living in the US are affected with this condition. It occurs in about 1 per 1,000 children.
There are three kinds of juvenile rheumatoid arthritis; Pauciarticular or oligoarticular JRA is the most common type, affecting less than five joints. Polyarticular JRA, on the other hand, occurs in approximately 30% of patients and affects at least five joints. Patients with polyarticular JRA may be diagnosed positive for rheumatoid factor, a specific antibody found in the blood. The last type is systemic JRA. This form is usually associated with fever, and can affect other organs, such as the liver and spleen.
Cause of Condition
There is still no known specific cause of juvenile rheumatoid arthritis. JRA is an autoimmune disorder, which means that the body attacks its own healthy tissues, specifically the joints. Proliferation of immune cells and infiltration into the synovium or joint spaces occur, resulting in joint inflammation.
Genetic factors do seem to play a role. Individuals who have family members diagnosed with an autoimmune disease are more likely to develop this condition. Various genes have been linked to its development, and are still currently being studied. The present theory is that juvenile rheumatoid arthritis develops in patients with a genetic predisposition and who are exposed to certain environmental factors, such as viruses.
Juvenile rheumatoid arthritis initially presents with non-specific symptoms. Patients experience weakness and poor appetite, and are noted to have decreased physical activity. They may also develop fever and a rash. Some children may be seen limping, which may be due to pain. Joint pain is typically noted to be more severe in the morning, with associated morning stiffness. Pain eventually improves throughout the day.
The key symptom of juvenile rheumatoid arthritis is the inflammation of the joints, particularly the knee, ankle or wrist. It can, however, involve other joints, such as the shoulders, hips, spine and even the jaw. Inflammation produces swelling, erythema or redness, and pain over the affected area. It can also result in limitation or loss of joint movement. Problems in bone development and growth can occur, resulting in discrepancies of leg lengths. The growth plates in the bones of children can become damaged, resulting in the premature union of the bones and stunted growth. Without adequate treatment, patients can eventually develop joint contractures. These contractures are permanent deformities caused by keeping the joints in a specific position for prolonged periods of time.
Aside from musculoskeletal and joint symptoms, juvenile rheumatoid arthritis can also have other manifestations, such as inflammation of the eye, also known as uveitis. If uncontrolled, this can result in blurring of vision and permanent damage to the eyes.
The spectrum of juvenile rheumatoid arthritis ranges from a self-limiting disorder to a chronic disease. Episodes of flares, wherein the symptoms worsen, and remissions, wherein the symptoms improve, are quite common in JRA. The condition can last for several weeks and resolve on its own, although symptoms may recur. In more than 50% of children with JRA, the disease disappears in adulthood. However, in more severe forms, the condition can persist and become a lifelong condition.
Who to See and Types of Treatment Available
The treatment of juvenile rheumatoid arthritis is focused on alleviation of symptoms and resumption of normal physical activities. A multidisciplinary team, composed of paediatric rheumatologists, physical and occupational therapists, and occasionally an orthopaedic surgeon, can best handle this condition. Regular ophthalmologic follow-up is also recommended, even in patients without eye symptoms, to monitor any eye involvement.
For symptom relief, management is directed at controlling the inflammation and pain. The first line of treatment is non-steroidal anti-inflammatory drugs, or NSAIDs, such as ibuprofen. COX-2 inhibitors, such as celecoxib, have also been shown to be effective. Steroids may also be given to reduce the swelling. These drugs are available in various forms, and may be administered via the oral, intramuscular (into the muscle) or intraarticular (into the joint) routes. For patients with more severe and polyarticular forms of JRA, stronger medications may be necessary to alleviate the inflammation. They may be given disease-modifying antirheumatic drugs, or DMARDs, such as methotrexate or azathioprine. These are powerful drugs that have the potential to weaken the immune system, making the patient susceptible to infections and producing other unwanted side effects. Because of these, these drugs should be taken with proper supervision from your physician. Newer medications, known as biologic response modifiers, are currently being studied to determine their suitability for use in patients with JRA.
Aside from medications, patients with juvenile rheumatoid arthritis are also advised to undergo physical therapy, wherein they are taught exercises to improve muscle and joint strength, and increase the range of motion of the joints. Patients are also recommended to undergo occupational therapy, where they are taught strategies to help them adapt to their environment and perform activities of daily living. These forms of therapy allow patients to function independently and improve their quality of life. Assistive and ambulatory devices may be necessary in some cases of JRA. Surgery is rarely needed, except in severe forms of the disease or when complications ensue. Joint replacement surgery is usually reserved after the patient’s growth has been completed. Significant improvements in the management of juvenile rheumatoid arthritis in the last couple of decades have allowed patients with this condition to live productively.
Prince FH, Otten MH, van Suijlekom-Smit LW. Diagnosis and management of juvenile idiopathic arthritis. BMJ. 2010 Dec 3;341:c6434.
Ruperto N, Lovell DJ, Quartier P, et al; Paediatric Rheumatology International Trials Organization and the Pediatric Rheumatology Collaborative Study Group. Long-term safety and efficacy of abatacept in children with juvenile idiopathic arthritis. Arthritis Rheum. 2010 Jun;62(6):1792-802.