What is juvenile idiopathic arthritis?
Juvenile idiopathic arthritis (JIA) is the most common type of arthritis that affects children. JIA is a chronic (long-lasting) disease that can affect joints in any part of the body.
JIA is an autoimmune disease in which the body’s immune system mistakenly targets the synovium, the tissue that lines the inside of the joint, and the synovial fluid in the joint. This causes the synovium to make extra synovial fluid, which leads to swelling, pain and stiffness in the joint.
This process can spread to the nearby tissues, eventually damaging cartilage and bone. Other areas of the body, especially the eyes, may also be affected by the inflammation. If it is not treated, JIA can interfere with a child’s normal growth and development.
What are the types of juvenile idiopathic arthritis?
There are several types of JIA, depending on the symptoms and the number of joints involved:
- Oligoarthritis: This type of JIA affects fewer than five joints, most often in the knee, ankle and elbow. It also can cause uveitis, an inflammation of the middle layer of the eye (the uvea). Uveitis may be undetectable without a dedicated eye exam. About half of all children with JIA have oligoarthritis; it is more common in girls than in boys. Many children will outgrow oligoarthritis by adulthood. In some children, it may spread to eventually involve more joints.
- Polyarthritis: This type of JIA affects five or more joints, often the same joints on each side of the body. Polyartritis can also affect the neck and jaw joints and the smaller joints, such as those in the hands and feet. It is more common in girls than in boys and accounts for 20 percent of JIA patients
- Psoriatic arthritis: This type of arthritis affects children who have arthritis and psoriasis, a rash that causes raised red patches or skin lesions covered with a silvery white buildup of dead skin cells. Psoriatic arthritis can also cause nail changes that look like dimpling or pitting.
- Enthesitis-related arthritis: Also known as spondyloarthropathy. This type of arthritis often affects the spine, hips and entheses (the points where tendons and ligaments attach to bones), and occurs mainly in boys older than seven years. The eyes are often affected in this type of arthritis, and may become painful or red.
- Systemic arthritis: Also called Still's disease, this type occurs in about 10 to 20 percent of children with JIA. A systemic illness is one that can affect the entire body or many body systems. Besides arthritis, systemic JIA usually causes persistent high fever and rash, which most often appears on the trunk, arms and legs when fever spikes. It can also affect internal organs, such as the heart, liver, spleen and lymph nodes. This type of JIA affects boys and girls equally and rarely affects the eyes.
How common is juvenile idiopathic arthritis?
JIA is the most common type of arthritis in children. It affects about 1 in 1,000 children, or about 300,000 children in the United States.
Symptoms and Causes
What causes juvenile idiopathic arthritis?
The causes of JIA are not known. Factors that may be involved, alone or in combination, include genetics (the disease may be inherited), infection and environmental factors that influence the immune system.
What are the symptoms of juvenile idiopathic arthritis?
Symptoms vary depending on the type of JIA and may include:
- Pain, swelling and tenderness in the joints. The joints may also feel warm.
- Morning joint stiffness
- Limping gait (younger children may not be able to perform motor activities that they recently learned)
- Weight loss
- Swollen lymph nodes
- Fatigue or irritability
- Eye redness, eye pain, and blurred vision
Diagnosis and Tests
How is juvenile idiopathic arthritis diagnosed?
Because there are no tests for JIA, the doctor will try to rule out other causes of arthritis and other diseases as the cause of the symptoms.
To diagnose JIA, the doctor will take a complete medical history that includes a description of symptoms and perform a physical examination. The doctor will also examine the joints for signs of arthritis.
The doctor may also order these tests:
- Imaging techniques such as X-rays or magnetic resonance imaging (MRI) to show the condition of the joints;
- Laboratory tests on blood, urine, and/or joint fluid to help determine the type of arthritis. These include tests to determine the degree of inflammation and the presence of the substances antinuclear antibody (ANA) and rheumatoid factor. These tests also can help rule out other diseases — such as an infection, bone disorder, or cancer — or an injury as the cause of the symptoms.
Management and Treatment
How is juvenile idiopathic arthritis treated?
The goals of treatment are to relieve pain, reduce swelling, increase joint mobility and strength, and prevent joint damage and complications. Treatment generally includes medications and exercise.
Medications used to treat JIA include the following:
- Nonsteroidal anti-inflammatory drugs (NSAIDs): These medicines provide pain relief and reduce swelling, but do not affect the course or prognosis of JIA. Some are available over the counter and others require a prescription. NSAIDs include ibuprofen (such as Motrin® and Advil®) and naproxen (such as Aleve®). These medicines can cause nausea and stomach upset in some people and need to be taken with food.
- Corticosteroids (steroids): Corticosteroids are often given as an injection (shot) into a single affected joint. These medications can also be taken orally (by mouth) as a pill, especially by patients with more widespread disease. Oral corticosteroids can have serious side effects, including weakened bones, especially when used for long periods. Doctors usually try to limit using long-term steroids in children because they can interfere with a child’s normal growth.
- Disease-modifying anti-rheumatic drugs (DMARDs): These medications work by changing, or modifying, the actual disease process in arthritis. The aim of DMARD therapy is to prevent bone and joint destruction by suppressing the immune system’s attack on the joints. Methotrexate is the DMARD most often used to treat JIA. Other medications used include sulfasalazine and leflunomide.
- Biological modifying agents: Biological agents are medications that directly target molecules or proteins in the immune system that are responsible for causing the inflammation. They are given by subcutaneous injection or intravenously and are used to treat children with more severe arthritis that has not responded to other medications. Biological agents must be used with caution because they suppress the immune system and make children more vulnerable to infection. These drugs include etanercept, infliximab, adalimumab, abatacept, anakinra, rilonacept, and tocilizumab.
Exercise and physical and occupational therapy can help reduce pain, maintain muscle tone, improve mobility (ability to move) and prevent permanent handicaps. In some cases, splints or braces also may be used to help protect the joints as the child grows. Special accommodations with schools may be needed to adjust for children with limitations from their arthritis.
What complications are associated with juvenile idiopathic arthritis?
If it is not treated, JIA can lead to:
- Permanent damage to joints
- Interference with a child's bones and growth
- Chronic (long-term) arthritis and disability (loss of function)
- Vision problems, including a loss of vision caused by uveitis (inflammation inside the eye)
- Inflammation of the membranes surrounding the heart (pericarditis) or lungs (pleuritis) in systemic JIA
Can juvenile idiopathic arthritis be prevented?
At this time, because the cause of JIA is unknown, there is no method to prevent the development of JIA.
Outlook / Prognosis
What is the prognosis (outlook) for children who have juvenile idiopathic arthritis?
JIA affects each child differently. For some, only one or two joints are affected and the disease is easy to control. For others, JIA may involve many joints and the symptoms may be more severe and may last longer.
With early detection and treatment, including physical and occupational therapy, it is possible to achieve good control of the arthritis, prevent joint damage, and allow normal or near-normal function for most children who have JIA.
What are some tips for children living with JIA?
Children with JIA should live life as normal as possible. Attending school, playing sports, participating in extracurricular and family activities regularly is encouraged. Exercise does not make symptoms of arthritis worse. In fact, exercise can help prevent deconditioning, increase muscle strength and muscle endurance to support the joints.
There is no evidence that shows special diets are effective for arthritis, so children can eat a standard, well-balanced diet.
Are there support groups for individuals with JIA?
The Arthritis Foundation is a leading non-profit organization that is dedicated to addressing the needs of adults and children living with arthritis in the United States. There are more than one hundred local offices throughout the U.S. Many local and national events are organized to educate and connect patients and families. To learn more visit https://www.arthritis.org/
Some information specific to children can be found at http://www.kidsgetarthritistoo.org/.