AND ANSWERS ABOUT JUVENILE RHEUMATOID ARTHRITIS
means joint inflammation, and refers to a group of diseases that
cause pain, swelling, stiffness and loss of motion in the joints.
"Arthritis" is often used as a more general term to refer to the
more than 100 rheumatic diseases that may affect the joints but
can also cause pain, swelling, and stiffness in other supporting
structures of the body such as muscles, tendons, ligaments, and
bones. Some rheumatic diseases can affect other parts of the body,
including various internal organs. Children can develop almost all
types of arthritis that affect adults, but the most common type
of arthritis that affects children is juvenile rheumatoid arthritis.
Is Juvenile Rheumatoid Arthritis?
rheumatoid arthritis (JRA) 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.
Doctors classify three kinds of JRA by the number of joints involved,
the symptoms, and the presence or absence of certain antibodies
in the blood. (Antibodies are special proteins made by the immune
system.) These classifications help the doctor determine how the
disease will progress.
Pauciarticular (paw-see-are-tick-you-lar): 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.
children have special proteins in the blood called antinuclear antibodies
(ANAs). Eye disease affects about 20 to 30 percent of children with
pauciarticular JRA. Up to 80 percent of those with eye disease also
test positive for ANA and the disease tends to develop at a particularly
early age in these children. Regular examinations by an ophthalmologist
(a doctor who specializes in eye diseases) are necessary to prevent
serious eye problems such as iritis (inflammation of the iris) or
uveitis (inflammation of the inner eye, or uvea). Many children
with pauciarticular disease outgrow arthritis by adulthood, although
eye problems can continue and joint symptoms may recur in some people.
Polyarticular: About 30 percent of all children with JRA have polyarticular
disease. In polyarticular disease, five or more joints are affected.
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. Some children with polyarticular
disease have a special kind of antibody in their blood called IgM
rheumatoid factor (RF). These children often have a more severe
form of the disease, which doctors consider to be the same as adult
Systemic: Besides joint swelling, the systemic form of JRA is characterized
by fever and a light pink rash, and may also affect internal organs
such as the heart, liver, spleen, and lymph nodes. Doctors sometimes
call it Still's disease. Almost all children with this type of JRA
test negative for both RF and ANA. The systemic form affects 20
percent 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.
Is Juvenile Rheumatoid Arthritis Different From Adult Rheumatoid
main difference between juvenile and adult rheumatoid arthritis
is that many people 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.
difference between JRA and adult rheumatoid arthritis is the percentage
of people who are positive for RF. About 70 to 80 percent of all
adults with rheumatoid arthritis are positive for RF, but fewer
than half of all children with rheumatoid arthritis are RF positive.
Presence of RF indicates an increased chance that JRA will continue
Causes Juvenile Rheumatoid Arthritis?
is an autoimmune disorder, which means 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 the immune system goes awry
in children who develop JRA. Scientists suspect that it is a two-step
process. First something in a child's genetic makeup gives them
a tendency to develop JRA; and then an environmental factor, such
as a virus, triggers the development of JRA.
Are the Symptoms and Signs of Juvenile Rheumatoid Arthritis?
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 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 (less than half), internal organs including
the heart, and very rarely, the lungs may be involved.
inflammation is a potentially severe complication that sometimes
occurs in children with pauciarticular JRA. Eye diseases such as
iritis and uveitis often are not present until some time after a
child first develops JRA.
there are periods when the symptoms of JRA are better or disappear
(remissions) and times when symptoms are worse (flares). JRA is
different in each child-some may have just one or two flares and
never have symptoms again, while others experience many flares or
even have symptoms that never go away.