JUVENILE RHEUMATOID ARTHRITIS:
The American College of Rheumatology has defined it as arthritis
of one or more joints with onset below the age of 16 years and persisting
for atleast 6 weeks with explicit exclusion of other specific diseases such
as juvenile ankylosing spondylitis, juvenile psoriatic arthritis, infectious
and post infectious arthritis and other rheumatic diseases. Prevalence is
in the range of 0.4 – 1.3 per 1000 children.
Juvenile Rheumatoid Arthritis is an autoimmune disease with
major histocompatibility complex (MHC) associated with genetic
predisposition. The classical IgM, Rheumatoid Factor is usually negative
but is believed that some children have hidden IgA Rheumatoid Factor.
Three major types of onset are described according to the
presentation during first 6 months of disease.
1. Pauciarticular onset JRA:
This accounts for about 60% of patients. Four or less joints usually
large are involved in an asymmetrical fashion. Joint swelling rather than
joint pain is the usual complaint.
2. Polyarticular onset JRA:
Occurs in 30% of patients and is common in girls. Five or more
joints (both large and small) are affected within the first 6 months ofonset. Increased joint pain in proportion to the degree of joint swelling is
the usual complaint. Fever and malaise can be significant.
3. Systemic onset JRA:
About 10% of patients with JRA may have an acute onset of the
disease with prominent systemic features that may precede the joint
manifestation. Illness usually begins as an intermittent fever with a
characteristic peak, twice daily. This is accompanied by a characteristic
maculopapular rash with central clearing. Hepatosplenomegaly and
lymphadenopathy are common. Pericarditis and interstitial lung disease
may be present. Antinuclear antibodies are positive but rheumatoid
factor is negative.
RA is not fatal, but complications of the disease may shorten
survival by a few years in some individuals. In general, RA is progressive
and cannot be cured. In some, the disease gradually becomes less
aggressive and symptoms may even improve. However, if bone and
ligament destruction and any deformities have occurred, the effects are
permanent. According to one survey, 70% of patients with RA believe
that the disease prevents them from living a fully productive life.
Lymphoma and other cancers: Alterations in the immune system
associated with RA may play a role in the higher risk for lymphoma
observed in patients with RA. Aggressive treatments for RA that suppress
the immune system may help preventing this cancer, but more research is
needed to evaluate this possibility. Other cancers that may occur with
increased frequency in patients with RA include prostate and lung
Macrophage activation syndrome: This is a life-threatening
complication of RA and requires immediate treatment. Patients should be
aware of symptoms, which include persistent fever, weakness,
drowsiness, and lethargy.