Juvenile Arthritis
Also known as: Juvenile Rheumatoid
Arthritis
What is it?
Juvenile arthritis (JA) refers to a chronic
inflammation of the joints in children. A chronic
condition is one in which the symptoms occur frequently,
over a long period of time.
Who gets it?
Juvenile arthritis (JA) affects children under 16 years
of age.
What causes it?
No definite cause of juvenile arthritis (JA) has been
identified. Researchers believe JA is a type of autoimmune
disease. Normally our bodies' immune cells attack and kill
what they see as foreign invaders, usually bacteria,
viruses, and fungi. However, with autoimmune diseases,
something causes the immune system to see the body's own
tissues as foreign invaders. When immune cells and
proteins, called antibodies, crowd into the joints, the
joint lining becomes inflamed. This causes swelling and
stiffness. Normally, with infections, the inflammation
goes away after the body has fought off the germs. With
chronic conditions, such as JA, however, the inflammation
recurs frequently or hangs on for a long time. No one
knows what triggers the body's immune reaction. Because JA
occasionally runs in families, there appears to be a
genetic link. Some researchers believe certain people are
more likely to develop an autoimmune disease because of
their genetic make-up.
What are the symptoms?
Children with juvenile arthritis (JA) have periods of
time when they have no symptoms, called remission,
followed by flare-ups. Some flare-ups last only a few
days; some last for months. The joints affected by JA have
a membrane, called the synovial membrane, that produces
synovial fluid to keep the joints lubricated and to help
the bones move smoothly around the joint. When the
synovial membrane becomes inflamed, it stiffens and
thickens, making it difficult to move the joint. This
constant inflammation damages protective tissue that
covers the end of a bone in the joint, called the
cartilage. With time, the joint can become deformed, the
cartilage can be destroyed, and the unprotected bone can
begin to wear away. Because the child may avoid moving the
painful joint, the muscles and tendons may shorten due to
lack of use. This shortening can lead to difficulty
straightening a joint which is called a contracture. The
bone in the affected area may grow either too quickly or
too slowly, so the child may have one limb that is shorter
than the other. This problem is most noticeable in
children with arthritis in one knee or ankle and not the
other leg (asymmetrical arthritis). Other symptoms include
redness and warmth around the affected joint, low fever,
loss of appetite, weight loss, and fatigue.
JA is classified into different subtypes depending upon
the symptoms that appear within the first six months that
the child develops the disorder. The most common type of
JA is called pauciarticular (or oligoarticular) JA. It
affects approximately 40 to 60% of all JA patients, and
has the least severe joint symptoms. With pauciarticular
JA, the inflammation affects fewer than four joints, and
is usually in the elbow, wrist, knee, and/or ankle. It
does not affect the child's overall growth, but may cause
differences in leg lengths if asymmetrical arthritis is
present. Pauciarticular JA seldom causes any joint
deformity. Some children, especially girls, may develop a
serious inflammation of the iris of the eye, called
chronic iridocyclitis (iritis or uveitis are alternate
names for this). It produces no symptoms, but can be
detected during an eye examination. If untreated, this
inflammation can rarely lead to blindness. Eye exams are
recommended every 3-4 months for at least 4 years from
diagnosis in most children with pauciarticular JA.
Symptoms of pauciarticular JA are characterized by
flare-ups and remissions, but some children go into
complete remission after a few years. Some children may
develop polyarticular JA after they have had
pauciarticular disease for a while. Polyarticular JA
affects around 30% of children diagnosed with JA. This JA
variant affects five or more joints at the same time,
usually the small joints of both hands and feet. It can
also affect the elbow, wrist, knee, ankle, jaw, neck, or
hips. Again, leg growth may be affected so one leg may be
shorter than the other. Other symptoms may include low
fever, mild rash, anemia (low red blood cell count), and
decreased growth and appetite.
Systemic onset JA, also called Still's disease, affects
the whole body, not just the joints. Approximately 20% of
all JA patients have systemic onset JA, and these children
are usually diagnosed between 5 to 10 years of age.
Symptoms begin with a high fever that usually peaks in the
evening; a flat, pale pink rash on the trunk and upper
arms or legs; appetite and weight loss; and enlarged lymph
nodes, spleen, and liver. The last symptoms to appear may
be joint and muscle pain, often around the legs and
ankles. The child may also become severely anemic. Other
complications can include inflammation of the sac
containing the heart or the heart itself (pericarditis;
myocarditis); or inflammation of the tissue lining the
chest cavity and lungs (pleuritis). Spondyloarthropathy is
a type of JA that is more common in boys over the age of 8
years. It usually first affects the lower extremity joints
and/or adjacent tendon attachment the it may later involve
the lower spine. The eyes may also become inflamed at
which time they are usually red and sore; chronic eye
damage is not common. Children with a skin condition
called psoriasis may develop a form of JA. Psoriatic JA
may appear similar to pauci or polyarticular JA. Children
with psoriatic JA may have a family history of psoriasis.
They will eventually have the rash, and early indications
may include pits or ridges in their fingernails.
How is it diagnosed?
Juvenile arthritis (JA) is diagnosed based upon a
pattern of symptoms. Your doctor will review your child's
medical history and symptoms, and perform a careful
examination, including an eye exam. He or she may order
blood tests to look for signs of inflammation, such as a
high white blood cell count. In some children with JA, a
test of the blood's erythrocyte sedimentation rate (ESR)
or how quickly red blood cells settle in a tube, will show
an increase. Children with JA may also have a marker
called C-reactive protein in their blood which measures
the amount of inflammation similar to the ESR. The red
blood cell count may be low, indicating anemia. Children
with polyarticular JA may test positive for an antibody in
the blood called rheumatoid factor (RF). RF is present in
adults with rheumatoid arthritis, and children who test
positive for RF usually have a more severe form of JA;
similar to adults, they are more likely to experience
joint deformity.
What is the treatment?
The treatment of juvenile arthritis (JA) centers around
decreasing joint inflammation, suppressing pain, and
preserving movement in order to prevent joint deformity.
This is commonly done with a combination of medication(s),
physical therapy and exercise. Nonsteroidal
anti-inflammatory drugs (NSAIDs), such as ibuprofen and
naproxen, are available over-the-counter and are effective
in relieving pain and swelling. Sometimes, steroid drugs
may be prescribed to be taken orally or injected directly
into the joint to quickly stop inflammation. Steroids are
avoided long term when possible because of the potential
for serious side effects. Steroid eye drops are used to
treat inflammation in the eye. Your doctor may prescribe
other drugs, called DMARDs (Disease Modifying
Anti-Rheumatic Drugs), such as methotrexate, sulfasalazine
and hydroxychloroquine, depending upon your child's
symptoms. Newer drugs called biologic agents (eg.
etanercept) may be prescribed for children with more
severe joint inflammation that doesn’t respond to NSAIDs
and DMARDs.
Non-drug treatments might include physical therapy to
keep the affected joints and muscles moving, splints to
support the inflamed joints, moist heat or cold packs, and
complete bed rest during severe flare-ups. Alternative
treatments have not been studied fully in children, but
these could be considered as additional treatment for some
JA patients. Examples of alternative treatments might
include relaxation techniques, meditation, hypnosis,
acupressure, acupuncture, yoga, and diet modifications.
Your doctor can help you decide which combination of
treatments is right for your child.
Self-care tips
Researchers have not yet determined children with JA
may also have a marker called C-reactive protein in their
blood. Follow your doctor's recommended treatment
plan to reduce the pain of flare-ups and prevent joint
deformity.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
|
