Arthritis, Juvenile Rheumatoid The 5 Minute Pediatric Consult


	Arthritis—Juvenile Rheumatoid

Elizabeth Candell Chalom

Database
Differential Diagnosis
Data Gathering
Physical Examination
Laboratory Aids
Therapy
Common Questions and Answers
Bibliography

DATABASE

DEFINITION

Juvenile rheumatoid arthritis (JRA) is chronic synovial inflammation of unknown etiology in at least one joint, for at least 6 weeks. Age of onset must be less than 16 years old. It can be subdivided into three major types.
Pauciarticular JRA is JRA affecting less than 5 joints.
- Type I usually affects young girls who are antinuclear antibody (ANA)-positive and usually begins in girls less than 6 years old.
- Type II (spondyloarthropathies) generally affects boys, many of whom are HLA-B27-positive, in late childhood or adolescence.
Polyarticular JRA affects 5 or more joints and can occur at any age.
Systemic-onset JRA is characterized by high, spiking quotidian or diquotidian fevers and an evanescent pink/salmon-colored macular rash. These children may also have lymphadenopathy, hepatosplenomegaly, pericarditis, or pleuritis. The arthritis may not appear until weeks to months after the onset of the systemic symptoms. Systemic-onset JRA can occur at any age.

CAUSES

The etiology of JRA is unknown, but genetic predisposition, autoimmunity, infection, and trauma may all play a role.

PATHOLOGY

Chronic synovial inflammation

EPIDEMIOLOGY

JRA affects approximately 70,000 children in the United States.
Affects girls twice as often as it affects boys, but pauciarticular type II usually affects boys (male:female ratio, 10:1).
Approximately 50% of children with JRA have the pauciarticular type.
40% have the polyarticular type.
10% have systemic-onset JRA.

GENETICS

Some studies have indicated that various HLA markers may be associated with different subtypes of JRA. For example, HLA-DR4 seems to be associated with rheumatoid factor-positive (RF1) polyarticular JRA, HLA-DR1 is associated with pauciarticular disease without uveitis, and HLA-DR5 is associated with pauciarticular JRA with uveitis.

COMPLICATIONS

Joint degeneration with loss of articular cartilage
Soft-tissue contractures
Leg-length discrepancies
Micrognathia
Cervical spine dislocations
Rheumatoid nodules
Growth retardation

Pauciarticular JRA, especially with a positive ANA, is also associated with a chronic uveitis, which can lead to loss of vision if not detected early with routine slit-lamp eye examinations. Pericarditis and pleuritis, as well as severe anemia, may develop in patients with systemic-onset JRA.

DIFFERENTIAL DIAGNOSIS

Monoarticular JRA
- Septic joint
- Trauma
- Hemarthrosis
- Villonodular synovitis
Monoarticular or pauciarticular JRA
- Lyme disease
- Acute rheumatic fever
- Malignancies
- Sarcoidosis
- Inflammatory bowel disease
Polyarticular JRA
- Viral or post-viral illness (especially parvovirus)
- Lyme disease
- Lupus
Systemic-onset JRA
- Infection
- Oncological process (leukemia)
- Inflammatory bowel disease
- Lupus

DATA GATHERING

HISTORY

Morning stiffness that improves after a hot shower/bath or with stretching and mild exercise is common in JRA.
The joints often become sore/painful again in the late afternoon or evening.
Patients with JRA generally do not complain of severe pain, but rather they avoid using certain joints that are particularly affected. If a child has severe pain in a joint, especially pain that seems out of proportion to the physical findings, diagnoses other than JRA should be entertained.
In systemic JRA the fever curve is important to document. Between fever spikes the child is completely afebrile. The rash is evanescent and the patients often have a history of fatigue, malaise, and weight loss.

PHYSICAL EXAMINATION

Arthritis must be present in at least one joint. There may be restricted range of motion in the affected joints and soft-tissue contractures as well.
- Enthesitis and sacroiliac tenderness are often seen in spondyloarthropathies.
In systemic JRA the rash, if present, is almost pathognomonic for this disease.
Lymphadenopathy and hepatosplenomegaly may be seen.
A careful cardiac and pulmonary examination must be done to look for pericarditis and pleuritis.

LABORATORY AIDS

No laboratory finding is diagnostic for JRA.
Many patients with JRA, especially the polyarticular and systemic types, have elevated sedimentation rates and anemia.
Patients with systemic JRA often have a leukocytosis, predominantly neutrophils, and thrombocytosis as well.
ANA is a useful test in classifying patients with JRA.
- Positive in 80% of pauciarticular type I
- 40% to 60% polyarticular
- 10% normal population
RF will be positive in 15% to 20% of patients with polyarticular arthritis. RF1 patients tend to behave like adult patients with rheumatoid arthritis with more aggressive and persistent arthritis and a worse prognosis.

IMAGING

Radiography is often normal early in JRA.
Later, if arthritis persists, loss of articular cartilage, joint fusion, and bone demineralization may be seen, as well as bone cysts and erosions.

THERAPY

DRUGS

Non-steroidal anti-inflammatory drugs (NSAIDs)
- First-line therapy for JRA
- If there is no response to the initial NSAID after 4 to 6 weeks of an adequate dose, a different one should be tried. Patients will often respond differently to the various nonsteroidal drugs.
If NSAIDs are ineffective in controlling the disease, a second-line agent should be added, such as hydroxychloroquine, sulfasalazine, or methotrexate.
Methotrexate: If the arthritis is severe, methotrexate is often started. Laboratory values must be monitored closely in these patients, looking for bone marrow suppression or elevation of transaminase levels.
Glucocorticoids: In systemic JRA with high fevers, glucocorticoids are often necessary, either as oral (daily or every other day) doses or as intravenous pulses, every 2 to 8 weeks. Steroids are also used for patients with polyarticular JRA whose arthritis is unresponsive to other medications. Because of the many side effects of systemic steroids, patients should be weaned off steroids as soon as possible.

PHYSICAL AND OCCUPATIONAL THERAPY

Physical and occupational therapy are important in the management of JRA. The goal is to maintain range of motion, muscle strength, and function.

DIET

Patients with systemic or polyarticular JRA, especially those on steroids, should maintain adequate calcium intake to minimize osteoporosis. Patients on methotrexate should take folate supplements daily, except on the days that the methotrexate is given.

WHEN TO EXPECT IMPROVEMENT

Responses to treatments for JRA vary tremendously.
- Some patients may respond to NSAIDs within a week or two.
- Others take 4 to 6 weeks to improve, or they may not respond at all.
- Steroids usually start to relieve symptoms within a few days.
- Hydroxychloroquine, can take 8 to 12 weeks until the maximum benefit is seen.
The waxing and waning nature of JRA itself adds to the variability of patient responses to treatments.

PROGNOSIS

Varies considerably
Children with pauciarticular JRA usually do very well and often go into remission within a year or two of starting treatment. They may have flareups, however, even up to 10 years after being symptom-free and off all medications.
Patients with polyarticular JRA who are RF1 often develop a severe arthritis that may persist into adulthood.
RF2 polyarticular patients generally do better.
50% of patients with systemic-onset JRA will develop chronic polyarticular disease.

PITFALLS

Overdiagnosis: arthritis must be present for at least 6 weeks before a patient can be diagnosed with JRA. Many viral illnesses can give joint pain and swelling that mimics JRA, but resolves within 4 to 6 weeks.

COMMON QUESTIONS AND ANSWERS

Q: Will the patient outgrow JRA?
A: In some studies, up to 50% of patients with JRA still had active disease 10 years after diagnosis. Only 15%, however, had any loss of function.

Q: Will siblings of patients with JRA develop the disease?
A: Rarely, but it can occur.

ICD-9-CM 714.30

BIBLIOGRAPHY

Aaron S, Fraser PA, Jackson JM, et al. Sex ratio and sibship size in juvenile rheumatoid arthritis kindreds. Arthritis Rheum 1985;28:753.

Singsen BH. Epidemiology of rheumatic diseases of childhood. Rheum Dis Clin North Am 1990;16:581–599.

Towner SR, Michet CJ JR, O’Fallon WM, et al. The epidemiology of juvenile rheumatoid arthritis in Rochester, Minnesota. Arthritis Rheum 1983;26:1208.

Wallace CA, Levinson JE. Juvenile rheumatoid arthritis: outcome and treatment for the 1990s. Pediatr Rheum 1991;17:891–905.

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