Juvenile Rheumatoid Arthritis

Juvenile rheumatoid arthritis (JRA) is an inflammatory form of arthritis that affects children, usually before the age of 16. Inflammation in a joint is the defining characteristic of most forms of arthritis. JRA involves inflammation and stiffness in a joint that lasts for more than six weeks. The joint may be red, swollen and sore, although the child may not complain of joint pain.

JRA is the most common form of juvenile arthritis. It may affect one joint or many joints. Like the rheumatoid arthritis that affects adults, JRA is a systemic disease and may also affect other systems in the body. Other than the joints, the eyes are the most common area affected. Some forms of JRA may also affect the skin and other organs such as the heart, lungs, liver and spleen.

JRA affects between 30,000 and 50,000 children in the United States, according to the Arthritis Foundation. It usually does not develop in infancy but can develop any other time in childhood. Certain types more commonly develop among 6- to 8-year-olds, whereas others occur in teenagers.

Juvenile rheumatoid arthritis affects the joints, where two or more bones meet. There are several types of joints. Arthritis occurs mostly in synovial joints, which can move, such as those in the hands, wrists, ankles, knees and feet. For each synovial joint, a space enclosed by the ligaments and adjoining bones forms a cavity called the joint capsule. The outer layer of the capsule is formed by a fibrous membrane.

The inside of the capsule is lined with a membrane called the synovium. This membrane secretes synovial fluid, which fills the joint capsule and provides lubrication. The ends of the bones encased in the capsule are cushioned in soft cartilage. The cartilage and synovial fluid permit the bones to move without rubbing against each other.

JRA is an autoimmune condition, which means people with JRA have an abnormal immune response. Normally, the immune system protects the body from outside invaders, such as germs. Immune cells, such as 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 autoimmune response, the immune system misidentifies normal body tissue as an outside invader. It attacks the tissue and tries to destroy it. In JRA, certain types of white blood cells attack parts of the synovium, causing the inflammation that characterizes JRA. The synovium then thickens, which causes the joint to swell. The synovium can form a body called a pannus, which has granular tissue that covers the bone and cartilage. The pannus tissue reacts with proteins called enzymes and erodes the bone surface.

The specific cause of JRA is 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 a genetic component is involved that makes a child more susceptible to developing JRA, but that some outside factor (e.g., viral infection) or a combination of factors trigger the initial inflammation.

JRA develops in several forms, which may affect a few joints in the body or many joints.

All forms of arthritis may cause joint pain and swelling. Such joint changes in JRA may affect the growth and proper development of bones in children.

Many children with JRA also 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. Some children also develop recurrent rashes. The most severe cases of JRA can affect the heart, lungs, spleen, liver and lymph nodes.

The course of JRA 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.

Most children eventually outgrow JRA and are not affected by it as adults. Some patients may experience joint problems as adults, especially if their bones were affected during a growth period. According to the National Institutes of Health, about 75 percent of children with JRA enter remission eventually with a minimal loss of function and deformity. Other cases of JRA may actually be the adult form of rheumatoid arthritis that began at an early age.

Juvenile rheumatoid arthritis (JRA) is divided into three categories, which are characterized by the number of joints and other body systems affected. These categories are:

The symptoms of juvenile rheumatoid arthritis (JRA) may take several weeks or months before they are noticeable. Children may experience joint pain or swelling but might not complain about it. Some may have stiffness, especially early in the morning or after a nap. A child with an affected knee may limp in the morning but get better later in the day.

The signs and symptoms may vary from day to day, or even within one day. Certain eye problems associated with JRA may have no symptoms.

Some children do not complain of pain, but parents or others may notice other signs of illness.

Juvenile rheumatoid arthritis (JRA) may be difficult to diagnose. Many children may not experience identifiable symptoms, or the symptoms they do have may be caused by other conditions, such as systemic lupus erythematosus, Lyme disease or bone disorders.

The first sign is usually a complain of joint pain or swelling by the child, or sometimes a limp noticed by parents. A diagnostic visit for JRA can be conducted by a child’s pediatrician. A pediatrician who suspects JRA 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 JRA, and thus may be used to classify which type of JRA is present. None of these tests definitively diagnose JRA.

Some of the blood tests include:

Another test that may be used for JRA 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 if the inflammation is caused by JRA or some other condition. Arthrocentesis is also used to diagnose any joint infection.

A diagnostic examination where JRA is suspected may also include x-rays. Images are taken of the affected joints and may help rule out other potential causes. Additional tests may also be used to rule out other potential bone problems, such as congenital deformities or bone cancer. These include CAT scans (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.

When JRA is suspected, a pediatrician will also refer the patient to an ophthalmologist, a physician who specializes in eye diseases. Children with JRA are susceptible to eye inflammations, which may not exhibit symptoms. The ophthalmologist may perform an examination with 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 (middle eye) that are subject to inflammation. Children with JRA should receive eye examinations by an ophthalmologist at least every six months.

Juvenile rheumatoid arthritis (JRA) cannot be cured, although many children outgrow the symptoms. Some children have mild symptoms for a few years. The goal of treatment is to maintain a high level of physical and social functioning. For others, JRA affects and deforms the joints, causing pain and interfering with growth. Most treatment plans for JRA involve regular monitoring of children and medications to ease their joint pain.

Exercise can be a regular part of a child’s treatment for JRA. Exercise helps to develop strong muscles and bones, keeps joints flexible and helps to build endurance. Some children may need physical therapy, occupational therapy or both to learn how to recover any lost range of motion, protect their joints and adapt to daily tasks. The 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 JRA and its effects can also prove beneficial. Joining a support group and explaining the disease to the child are helpful in coping with this chronic illness.

Regular monitoring of JRA and its effects on other systems is essential. Children with JRA require eye examinations by an ophthalmologist at least every six months.

The most common treatments for JRA are medications. A range of prescription and nonprescription medications are used to alleviate the pain and inflammation. Some of the medications used to treat JRA include:

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. Sometimes complimentary or alternate therapies, such as acupuncture, can be incorporated in treatment if the physician thinks it may help the child.

Surgery is rarely used to treat JRA. Certain types of arthroplasty might be recommended in some severe cases where a joint has become damaged.

People often outgrow the symptoms of JRA, and during childhood the disease need not be debilitating. One recent study found that, unlike some other rheumatic diseases, JRA was not linked with cognitive, emotional or social problems in children.

There is no way to prevent JRA. However, early intervention and careful monitoring of children with JRA can limit the progression of the disease.