Children sometimes complain about aches in their joints. A joint is where the ends of bones meet, such as the knee joint, shoulder joint, or the small joints in the fingers and toes. Joint pain in children can be caused by a variety of things. But if a child's joints are swollen for 6 weeks in a row or longer, he or she may have juvenile arthritis (JA).
Juvenile arthritis is a long-lasting, chronic disease. It is the most common form of arthritis in children. In the United States, it affects nearly 250,000 children under the age of 16 years.
There are several types of juvenile arthritis. Nearly all of them are different from rheumatoid arthritis in adults. This is why the term "juvenile rheumatoid arthritis (JRA)" is no longer widely used.
Juvenile arthritis is an autoimmune disease. This means that the body attacks its own healthy cells and tissues. Arthritis results from ongoing joint inflammation in four steps:
- The joint becomes inflamed
- The joint stiffens (contracture)
- The joint suffers damage
- The joint's growth is changed
In some cases, symptoms of juvenile arthritis are mild and do not progress to more severe joint disease and deformities. In severe cases, juvenile arthritis can produce serious joint and tissue damage. It can also cause problems with bone development and growth.
For many years it was believed that most children eventually outgrow juvenile arthritis. Now it is known that half of the children diagnosed with juvenile arthritis will continue to have active arthritis 10 years after diagnosis unless they receive aggressive treatment.
There are three main types of juvenile arthritis. This classification is based on symptoms, the number of joints involved, and the presence of certain antibodies in the blood. Doctors classify juvenile arthritis to help them predict how the disease will progress.
The three main types of juvenile arthritis are oligoarticular, polyarticular, and systemic.
Oligoarticular (formerly known as pauciarticular) means "few joints." In this type of juvenile arthritis, just a few joints are affected. About 50% of children with juvenile arthritis have the oligoarticular type. Girls younger than 8 years of age are more likely to develop it.
In half of the children with oligoarticular juvenile arthritis, only one joint is involved, usually a knee or ankle. This is called monoarticular juvenile arthritis. In most cases, this arthritis is very mild and over time the symptoms may lessen or go away altogether.
For some children, this arthritis affects four or fewer larger joints. Joints affected include the knee, ankle, or wrist. Involvement of fingers or toes is unusual.
Oligoarticular juvenile arthritis may also cause eye inflammation. To prevent blindness, your child may need regular eye examinations from a doctor who specializes in eye diseases (ophthalmologist). Eye problems may continue into adulthood.
About 30% of children with juvenile arthritis have the polyarticular type. This type of arthritis is more common in girls than in boys.
Polyarticular juvenile arthritis affects five or more smaller joints (such as the hands and feet). Usually, the affected joints are on both sides of the body. This type of juvenile arthritis can also affect large joints.
Children with a certain antibody in their blood, called IgM rheumatoid factor (RF), often have a more severe form of the disease. Antibodies are proteins in the blood usually used by the body to fight off infection through an immune response. In this form of arthritis, the IgM RF antibody attacks the body's own tissues. Doctors believe that this is the same type of arthritis as adult rheumatoid arthritis.
About 20% of children with juvenile arthritis have the systemic type.
This type of juvenile arthritis causes swelling, pain, and limited motion in at least one joint. Additional symptoms include rash and inflammation of internal organs such as the heart, liver, spleen, and lymph nodes. A fever of at least 102 degrees each day for 2 weeks or longer suggests this diagnosis.
If not adequately treated, children with systemic juvenile arthritis may develop arthritis in many joints and have severe arthritis that continues into adulthood.
No one knows exactly what causes juvenile arthritis. Researchers believe some children have genes that make them more likely to get the disease. Exposure to something in the environment (for example, a virus) triggers juvenile arthritis in these children. Juvenile arthritis is not hereditary, so it is very rare for more than one child in a family to get it.
Juvenile arthritis affects each child differently and can last for indefinite periods of time. There may be times when symptoms improve or disappear (remissions). There are other times when symptoms worsen (flare-ups). Sometimes, a child may have one or two flare-ups and never have symptoms again. Other children may have frequent flare-ups and symptoms that never go away.
The most common symptoms of juvenile arthritis include:
- Painful joints in the morning that improve by afternoon. Sometimes, the first sign of the disease is a morning limp, caused by an affected knee. Hands and feet may also be affected.
- Joint swelling and pain may also be noted. Although young children may not complain of pain, a child may feel irritable or tired and not want to play. Sometimes, juvenile arthritis causes lymph node swelling in the neck and other parts of the body.
- Joints may become inflamed and warm to the touch. In fewer than half of cases of juvenile arthritis, internal organs may become inflamed.
- Muscles and other soft tissues around the joint may weaken.
- In certain cases, children have a high fever and light pink rash, which may disappear very quickly.
- Some children develop growth problems. Joints may grow too fast or too slowly, unevenly, or to one side. This can make one leg or arm longer than the other. Overall growth also may slow.
- Some children with juvenile arthritis have eye problems, called iridocyclitis. This is treatable by an ophthalmologist (eye doctor). The presence of eye problems helps to confirm the diagnosis. Without treatment, iridocyclitis can result in eye damage that cannot be cured. Most patients do not have any symptoms with iridocyclitis and the only way to diagnose this early is by slit lamp examination.
Early diagnosis and treatment can control inflammation, relieve pain, prevent joint damage, and maintain a child's ability to function.
Your doctor will order a wide range of tests. A complete medical history and physical examination, blood tests, and x-rays will help your doctor rule out other conditions that cause arthritis.
Your doctor will review your child's complete medical history.
He or she will want to know how long your child has had problems with joint pain and swelling, and whether the symptoms have gotten better or worse. Your doctor will want to know whether your child feels stiff when getting up after rest, and whether the joints are swollen. He or she will look for other causes of the symptoms, such as an injury, another illness — such as Lyme disease — or a family history of autoimmune diseases.
Your doctor will examine your child's joints. He or she will check for signs of swelling, warmth and decreased range of motion. Your doctor will also examine the muscles near the affected joints, looking for signs of shrinkage (atrophy).
Tests on blood, joints, and tissue fluids can help to rule out other conditions that might cause similar symptoms. These tests may also be used to classify the type of juvenile arthritis.
X-rays provide clear images of dense structures like bone. Your doctor may order them to look for injuries to bone or for any unusual development of bone.
A child with juvenile arthritis will probably need treatment from a pediatric rheumatologist. This doctor specializes in helping children with arthritis and related conditions.
Treatment of juvenile arthritis is designed to reduce swelling, maintain full movement of affected joints, and relieve pain. Because juvenile arthritis may have complications, such as joint contracture, soft-tissue damage (such as tendons), or joint problems, any treatment program will also identify, treat, and prevent complications.
Medications. The most important part of any treatment plan for juvenile arthritis is medication. Your child may need certain medications for several years until juvenile arthritis is no longer active. Your child's doctor will determine when it is time to discontinue the medications after joint pain, swelling, and warmth disappear.
- Nonsteroidal anti-inflammatory drugs (NSAIDs) are often the first type of medication recommended. These are usually ibuprofen or naproxen and are used primarily to reduce inflammation and relieve pain. NSAIDs will help calm down the disease.
- Disease-modifying anti-rheumatic drugs are the next step if NSAIDs do not relieve symptoms. Disease-modifying anti-rheumatic drugs slow or stop progression of juvenile arthritis, but may take weeks or months to relieve symptoms. The most commonly used drug is methotrexate. Azulfidine is occasionally prescribed. Your doctor may want your child to take disease-modifying anti-rheumatic drugs along with nonsteroidal anti-inflammatory drugs.
- Biologic agents are a new class of drugs that also slow or stop the progression of the disease. These are usually only used if the disease-modifying anti-rheumatic drugs do not seem to work or if the patient has arthritis of the sacroiliac joint.
- Corticosteroids are stronger medications that may be used in treating severe juvenile arthritis. Given by mouth (orally) or injected into a vein (intravenously), corticosteroids can reduce serious symptoms, such as inflammation of the sac around the heart. If only one or two joints are involved, corticosteroids may be injected directly into the joint. Corticosteroids, however, can cause unwanted side effects, such as interfering with a child's growth, weight gain, weakened bones, and increased susceptibility to infections. It is important to follow the doctor's instructions exactly when taking corticosteroids.
Therapy. Exercise helps maintain muscle tone. It also helps preserve and recover joint range of motion and function. Your doctor may recommend a physical therapist to design an appropriate exercise program. It is important to balance activity with rest.
Although pain sometimes limits sports and physical activity, children with juvenile arthritis can often fully participate when symptoms are under control. Swimming is a particularly good exercise, because it uses many joints and muscles, without putting weight on the joints. In some cases, splints and other devices can help maintain joint alignment.
Splints. Splinting is useful in children with juvenile arthritis, either at night or during the day, to reduce inflammation and prevent contractures. Splints (braces made of plastic or other materials) are often used in the arm and hand to prevent contractures of the fingers and wrists.
Additional options. In addition to medications, warm baths or an electric blanket may help soothe sore joints.
Surgery is not often needed in treating juvenile arthritis. In very severe forms of juvenile arthritis or with very severe complications, surgery may be necessary to improve the position of the joint. An example of this might be when a joint has become deformed.
Joint replacement — frequently used to treat adults with arthritis — has almost no place in treating children.
There are many treatment options for juvenile arthritis. The primary goal of all treatment options is to induce remission of the arthritis. Treatment also focuses on preserving children's quality of life by making it possible for them to participate in play, sports, school, and social activities.
In addition to treatment options, a child's school and teachers can be an important resource. They may be able to develop helpful lesson plans that teach classmates about juvenile arthritis.
With proper attention, most children with juvenile arthritis progress normally through their school years.
Reviewed by members of POSNA (Pediatric Orthopaedic Society of North America)
The American Academy of Orthopaedic Surgeons
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