Juvenile arthritis (JA) refers to numerous childhood conditions that involve joint pain and inflammation, usually persisting more than six weeks. Although many people consider arthritis a disease of adults, children can contract most forms of it. Juvenile rheumatoid arthritis is the most common type seen in children.

The cause of JA is not well understood. Most types are autoimmune diseases, which means the immune system mistakenly attacks normal tissues.

JA may affect only a few joints, frequently the knee, ankle, hip, wrist, elbow or lower spine. Other types of JA affect many joints as well as other parts of the body. Many JA patients have inflammation in the eyes, which requires regular monitoring because it may not produce symptoms.

Physicians may use multiple blood tests and a physical examination to diagnose the various forms of JA. There is no known cure, but most children outgrow the symptoms when they reach adulthood.

Treatment depends upon the kind of arthritis and concentrates on pain relief and protection of growing joints. Drug treatment may include basic pain relievers or nonsteroidal anti-inflammatory drugs. Other drugs modify the disease progress or work on malfunctioning parts of the immune system. Exercise, physical therapy and occupational therapy may also be a part of treatment. Most children with JA are able to live healthy and active lives.

Juvenile arthritis (JA) is a broad term for several painful conditions that affect the joints in children. Joint pain that lasts longer than six weeks in a child under age 16 may be diagnosed as some form of arthritis.

Although arthritis is frequently considered a disease of adults, children can develop some form of most kinds of arthritis. Some forms of arthritis that affect adults may even begin in childhood. Almost 300,000 American children have some form of arthritis or other rheumatic disease, according to the Centers for Disease Control and Prevention (CDC).

Most forms of arthritis are rheumatic conditions, meaning they involve some sort of inflammation, usually of the soft tissue (cartilage) or membranes (synovium) surrounding the body’s joints. Other arthritic conditions may primarily involve inflammation of supporting structures, such as muscles, ligaments or tendons. In time, the inflammation may also cause swelling, redness and difficulty moving the joints. The joint may be red, swollen and sore, although the child may not complain of pain.

For adults, the swelling and inflammation of arthritis may mean joint pain and some disability. A complication within JA is that any injury or inflammation in a joint may affect a child’s growth and development of bones, though many children eventually outgrow the symptoms of JA and are not affected by it as adults.

Arthritis develops in many ways. Most forms of JA are autoimmune disorders, in which the body attacks its own tissue in the joints. Children with JA have an abnormal immune response. Normally, the immune system protects the body from outside invaders, such as germs. Immune cells (e.g., white blood cells) attack these invaders and flush them out or make them inactive. Part of this process normally produces some inflammation in tissue.

For someone with an autoimmune response, the immune system misidentifies regular body tissue as an outside invader. It attacks the tissue and tries to destroy it. In JA, certain types of white blood cells attack parts of the synovium, causing the inflammation that characterizes arthritis. The process by which this occurs is not well understood. The synovium thickens, which causes the joint to swell.

JA usually does not develop in infancy, but can develop any other time in childhood. Certain types more commonly develop among children between the ages of 6 and 8, whereas others occur in teenagers.

JA develops in several forms, which may affect a few joints in the body or many joints. Joints commonly affected by JA include:

• Hips, knees and ankles
• Shoulders, elbows, wrists and hands
• Neck
• Lower spine
• Jaw

Many children with JA also may experience inflammations in the eye. Some of the inflammations involve the uveal tract, the middle layer of the eye that includes the iris, ciliary body and choroid. Some of these inflammations may not have symptoms but can cause vision problems if left untreated.

Other forms of JA affect the skin, causing recurrent rashes or scaly patches of skin. The most severe cases of JA affect whole body systems, including the heart, lungs, spleen, liver and lymph nodes.

The course of JA may vary. Some children may have mild joint pain for a few months or a year. For others, the symptoms are recurrent over years and may affect their activity levels and result in frequent absences from school. Children may be reluctant to exercise or participate in activities because of pain.

Researchers have found that juvenile arthritis increases the risk of fractures and possibly osteoporosis later in life. The reasons for this may include inflammation, physical inactivity, weakness, delayed puberty, inadequate nutrition and side effects of corticosteroid therapy.

In addition, even nonarthritic children who suffer athletic injuries or other trauma, such as a knee meniscus injury or a fracture, face increased risk of developing osteoarthritis in adulthood. Osteoarthritis is by far the most common form of arthritis in adults.

More than 100 conditions can be classified as arthritis. Most of the forms that affect adults also affect children. The most common types of juvenile arthritis (JA) include:

• Juvenile rheumatoid arthritis (JRA). This is the most common form of arthritis that affects children. JRA may affect a few joints, many joints or the entire system. Children with JRA may have complications that involve inflammation in the eyes, heart, lungs and spleen. There are three categories of this disease:
  
  
• • Systemic JRA. Involves joint swelling and pain in many areas of the body, as well as fevers, swollen lymph nodes and rash. Systemic JRA is also known as Still's disease. It can develop later in life as adult-onset Still's disease.
    
    
  • Polyarticular JRA. Involves five or more painful and swollen joints, and may develop into rheumatoid arthritis. This condition often affects the same joint on both sides of a child's body. This condition is more common in girls than in boys. It normally lasts for several years until symptoms gradually diminish.
    
    
  • Pauciarticular JRA. Affects four or fewer joints. This condition accounts for roughly half of the cases of JRA.
    
    
• Juvenile spondyloarthropathy. Arthritis that generally affects people over the age of 10. The condition is more common in boys than in girls. The joint inflammation common with this condition usually persists into adulthood and tends to affect the spine and legs. There are several types of spondyloarthropathy, including:
  
  
• • Juvenile ankylosing spondylitis. Arthritis that inflames the joints between the vertebrae in the back, joints in the pelvis and the areas where the bones connect to tendons and ligaments. Systemic complications may involve the heart valves, lungs and eyes.
    

• • Juvenile reactive arthritis. Arthritis that develops in reaction to an infection in the body. Many cases are reactions to bacterial infections in the gastrointestinal system. However, only a small percentage of children with these infections go on to develop reactive arthritis. A common type of juvenile reactive arthritis is juvenile Reiter's syndrome. Children with this condition experience inflammation in the joints (arthritis), urinary system (urethritis) and the lining of the eye (conjunctivitis).
    
    
  • Juvenile psoriatic arthritis. May include a rash of scaly patches on the skin and pitted nails and affects the large joints in the same way as ankylosing spondylitis. Some children may develop the arthritis symptoms before the psoriasis. Some may also have family members with psoriasis or with other forms of arthritis.
    
    
  • Juvenile enteropathic arthritis. Condition that involves arthritis in the spine and large joints (e.g., knees, hips) and inflammatory bowel diseases, such as Crohn's disease or ulcerative colitis. In some children, the arthritis symptoms may begin years before the bowel problems.
    
    
  • SEA syndrome (seronegativity, enthesopathy, arthropathy). A condition that is often diagnosed when a child has one of the juvenile spondyloarthropathies but the condition cannot be classified into a more clear-cut category.
    
    
• Juvenile dermatomyositis. Autoimmune condition that causes skin rashes, weak muscles near the trunk of the body and fever. This type of myositis may also cause swollen joints in some children.
  
  
• Juvenile scleroderma. A rare disease in children that involves hard skin and inflammation in the muscles, joints and tendons. A systemic form of the disease may involve the kidney, lungs or heart.

Other conditions can also cause arthritic pain in children, including lupus and Lyme disease.

For most forms of juvenile arthritis (JA), the cause is unknown (idiopathic), which is why the disease is sometimes called juvenile idiopathic arthritis.

For forms such as juvenile reactive arthritis, an infection may trigger the inflammation in joints, but the reasons are not well understood. Although the immune system attacks the tissue in the joints, no one knows what triggers such an attack. Some researchers think that the child may have some genetic component that increases the susceptibility to developing JA, but that some outside factor (e.g., virus) or a combination of factors triggers the initial inflammation.

JA often appears after an infection or injury, though neither of these events is a direct cause of the arthritis. Some physicians theorize that these events can cause the immune system to respond inappropriately and mistake something in the body for an infection, even when the infection has passed. This reaction may cause the continuing inflammation.

Studies show that a genetic marker called HLA-B27 can be found in some people with certain forms of arthritis and other autoimmune conditions. About 5 to 7 percent of Caucasian people without autoimmune conditions have this gene, according to the National Institutes of Health. However, among patients with ankylosing spondylitis and Reiter's syndrome, 80 to 90 percent or more have the gene. The presence of HLA-B27 cannot predict arthritis or some other disease, but researchers are studying the association.

Juvenile arthritis (JA) is often difficult to detect because children may not complain about their pain. The symptoms of the condition may take weeks or months to become noticeable.

Many conditions develop their symptoms separately. For example, juvenile reactive arthritis develops its joint pain several weeks after an infection, usually in the gastrointestinal system in children.

The most common symptoms associated with JA include:

• Joint stiffness, pain or swelling. May be more noticeable in the morning or after a nap. The joint symptoms may vary from mild back pain to swollen, sausagelike fingers or toes.
  
  
• Fatigue and irritability.
  
  
• Unexplained fever.
  
  
• Skin problems. May include pink rashes and scaly skin patches.
  
  
• Eye problems. Can include redness, eye pain and sensitivity to light.
  
  
• Swollen lymph nodes.

There may be no external signs of a swollen joint in a child. These factors can make it difficult to detect if a child's joints are inflamed. In these cases, a parent may need to notice some other signs of illness, including:

• Limping
• Reluctance to use an arm or leg
• Uneven growth in limbs or gait disturbances
• Reduced level of activity
• Changed dental or eating habits as a result of jaw pain, dental pain or orofacial pain

Juvenile arthritis (JA) may be difficult to diagnose. Many children may not experience identifiable symptoms, and the symptoms they do have may be caused by other conditions, such as lupus, Lyme disease or bone disorders. Also, joint swelling may not be immediately obvious or may not be the first symptom to show in a child.

Parents may notice the child limping or not using a limb because of pain and stiffness. Diagnosis typically begins with the child's pediatrician. A pediatrician who suspects some form of JA may refer the case to a pediatric rheumatologist, a physician who specializes in arthritis and other inflammatory diseases in children.

A physical examination includes checking the joints for swelling, warmth, tenderness and range of motion. The physician notes descriptions and incidences of pain and its duration. The physician may try to move various joints to see if motion causes pain. The diagnosis will also include a medical history, including any family history of arthritis or autoimmune conditions, previous injuries or surgeries and general use of the joints. The physician will also note any fevers, rashes or infections.

Many laboratory tests are used to screen for specific kinds of arthritis or other diseases. Certain blood tests may produce characteristic results for some types of JA. However, none of these tests definitively diagnose JA. Some of the blood tests used include:

• Complete blood count (CBC). Measures the levels of different types of blood cells. Children with certain types of JA may show a low count of red blood cells (anemia) and higher counts of white blood cells.
  
  
• Erythrocyte sedimentation rate (ESR or sed rate). When elevated, indicates inflammation, which may be related to many forms of infection.
  
  
• Antinuclear antibody (ANA) test. Tests for certain autoimmune disorders such as lupus. Children with certain types of juvenile rheumatoid arthritis (JRA) test positive and are more likely to develop eye inflammations. Children with other types of JRA usually test negative for ANA.
  
  
• Rheumatoid factor test. Identifies the presence of the rheumatoid factor antibody. Absence or presence of the antibody may help a physician define a specific type of JA. For example, the antibody is common in certain forms of JRA but absent for others.
  
  
• HLA-B27 test. Presence of this genetic marker in the white blood cells may indicate many conditions, including ankylosing spondylitis, some types of JRA and Reiter's syndrome.

Another test that may be used is a synovial fluid analysis. Fluid from an affected joint is withdrawn with a needle (a procedure called arthrocentesis). Examining this fluid may help determine whether inflammation or infection is present, as well as what is causing the inflammation.

A diagnostic examination where JA is suspected may also include x-rays. Images are taken of the affected joints and may help rule out other causes. Other tests may also be used to rule out other potential bone problems such as congenital deformities or bone cancer. These include a CAT scan (computed axial tomography), where multiple x-ray images are taken, and MRI (magnetic resonance imaging), which uses powerful magnets to form an image of the bone and tissues.

For many forms of JA, other specialists may be involved to address conditions that affect other parts of the body. An ophthalmologist (physician who specializes in eye diseases) may examine JA patients who are susceptible to eye inflammations, which may not cause symptoms. The ophthalmologist may use a device called a slit lamp, which has high-intensity light that can be focused in a narrow area. It is used to examine some of the structures of the eye, such as the iris and other parts of the uveal tract that are subject to inflammation.

A dermatologist (physician who specializes in skin diseases) may be consulted for conditions that affect the skin, such as psoriatic arthritis or juvenile dermatomyositis.

There is no known cure for juvenile arthritis (JA), although many children outgrow the symptoms. For some children, the symptoms, especially joint pain, may continue into adulthood. During childhood, the focus of treatment remains in protecting the joints and maintaining proper bone growth and development. Most treatment plans for JA involve regular monitoring of children and medications to ease their joint pain.

Exercise, physical therapy and occupational therapy can be a regular part of treatment. Parents may be reluctant to have their children exercise because of pain or inactivity. However, a physician and physical therapist can provide guidance for safe levels of exercise that help recovery. Some children may need a specific therapy plan to learn how to recover any lost range of motion and how to protect their joints. A physical or occupational therapist may recommend ways to maintain a child's normal bone growth, such as splints or joint-protection techniques. Treatment plans that educate family members and the child's school community about JA and its effects can also prove beneficial. Usually a therapist works with a school therapist to address issues at school.

Heat and water treatments - thermotherapy and hydrotherapy - may also help relieve pain and increase range of motion.

Regular monitoring of JA and its effects on other systems is essential. Children with types of JA that have eye complications should receive eye examinations by an ophthalmologist (physician who specializes in eye diseases) at least every six months or more often if recommended. Dentists should also be aware of children diagnosed with JA. Arthritis pain in the jaw may make chewing difficult or make children more reluctant to brush their teeth.

The most common treatments for JA are medications. An entire range of prescription and nonprescription medications are used to alleviate pain and inflammation. Medications used to treat JA include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs). These drugs are used to reduce pain and inflammation. They are considered the first line of treatment for most forms of JA. Many children respond to NSAIDs without additional drugs. NSAIDs come in prescription and nonprescription forms. Some may affect renal or gastrointestinal function. Aspirin is generally not recommended for children because of the risk of Reye's syndrome, a rare but potentially fatal condition that affects organs through the body.
  
  
• Disease-modifying antirheumatic drugs (DMARDs). This category includes many types of drugs that suppress the autoimmune response of juvenile rheumatoid arthritis (JRA) and other conditions. They are a second line of treatment, after NSAIDs. DMARDs work long–term and can take several months to produce results. All DMARDs have some side effects, including gastrointestinal problems, serious liver or kidney complications, rashes or repressed immune responses to infection. DMARDs are often taken months or years after symptoms have disappeared to ensure that arthritis does not recur.
  
  
• Biologic response modifiers (BRMs). Drugs that slow progression of the disease and inhibit the production of the proteins called cytokines, which contribute to inflammation. BRMs block proteins that cause inflammation, such as tumor necrosis factor (TNF) or interleukin-1. These drugs may be prescribed for some children with ankylosing spondylitis and some with JRA who have not experienced relief from other treatments.
  
  
• Corticosteroids. Used for their immunosuppressant and anti-inflammatory qualities. They may be given intravenously or as pills for certain forms or as an injection in one inflamed joint. For serious cases of JRA, corticosteroids may be used to stop systemic symptoms such as pericarditis (inflammation of the heart sac). Corticosteroids are used with caution in children because they may interfere with growth, weaken bones and increase susceptibility to infections, fractures, osteoporosis, diabetes and other conditions, especially if taken for a long period of time. Corticosteroids in eyedrop form may be used for eye inflammation related to JRA. Some topical corticosteroid creams are used for psoriatic arthritis.

• Antibiotics. Forms of JA that involve bacterial infection, such as juvenile Reiter's syndrome, may require antibiotics.

All medications have some side effects, which may vary from patient to patient. Physicians monitor their patients and may adapt the medications depending on response and side effects.

Surgery is rarely used for juvenile forms of arthritis. In some cases, surgical repairs are made to bones that grow unevenly because of arthritis. However, most physicians wait until children are grown to evaluate the health of their bones and determine that the arthritis flare-ups have ended.

Splints may also be used in cases where inflammation threatens to cause severe damage to joints or deformities. Splints can be worn during sleep or rest to hold a child's joint in a more therapeutic position, or a child can wear the splints during the day to help protect a joint during a specific activity, such as writing.

There is no known way to prevent JA. However, early intervention and careful monitoring of children with these diseases can limit its effect on the child into adulthood. Healthy levels of exercise (approved by a physician) can help maintain muscle strength and minimize the likelihood of joint injury.

Parents or guardians of children with JA should try to make life as close to normal as possible for their youngsters. Regular attendance at school and participation in extracurricular activities if possible is usually recommended. Although a child with JA will require special treatment in many instances, parents should try not to become overly permissive or blame the child for the condition. Educating teachers, coaches and other authority figures in a child's life on the facts of JA can help make the child's life outside the home more normal. Joining a support group and explaining the disease to the child is helpful in coping up with this chronic illness.

Though JA does not have a cure, proper treatment should allow a child to achieve normal physical, social and intellectual development.

Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients or parents may wish to ask their doctor the following questions about juvenile arthritis (JA):

1. What type of JA does my child have?
   
   
2. Which tests differentiate among the types of JA?
   
   
3. What do these tests involve? Do we need to do anything to prepare for them?
   
   
4. Which prescription medications will help alleviate JA pain?
   
   
5. What side effects or risks do the drugs have?
   
   
6. Can any other treatments help?
   
   
7. Will my child outgrow this condition?
   
   
8. What types of sports can my child play with JA?
   
   
9. How can we tell when to rest and when to be physically active?
   
   
10. What are the chances other children in our family will develop JA?
    
    
11. Should these other children undergo any kind of testing or monitoring?