Juvenile idiopathic arthritis (JIA) – formerly also called juvenile rheumatoid arthritis (JRA) or juvenile chronic arthritis (JCA) – is defined as joint inflammation lasting more than six weeks in a child or adolescent younger than 16 years of age. This is the most common type of childhood arthritis, affecting about 1 in 1,000 children and teens in the United States. The exact cause of JIA is not known, but it is thought to be due to a combination of genetic predisposing factors and the environment. JIA is considered a chronic condition, meaning that these symptoms may last for a long time, and sometimes continue into adulthood. There are several different types of JIA, which are based on the number of joints with arthritis, the types of joints affected, and other symptoms your child or teenager may have. These types include:
Other types of JIA with a much different set of causes, symptoms and treatment include:
Children with arthritis may experience a wide variety of symptoms. Children may develop pain, swelling, stiffness or warmth in their joints. Frequently, younger children may not complain of pain at all, but they may develop a limp or have difficulty using their fingers. Joint symptoms are typically worse first thing in the morning or after a period of rest, and then improve throughout the day as the child becomes more active. Children with oligoarticular JIA usually have involvement of larger joints such as the knees or ankles, while those with psoriatic or polyarticular JIA may also have involvement of small joints, such as the fingers and toes. Because arthritis is associated with inflammation, the child may feel tired, have a decrease in appetite, or have slow growth. JIA can also be associated with eye disease such as uveitis, which may cause symptoms such as redness and decreased vision, or may cause no detectable symptoms.
There is no one specific test to diagnose juvenile idiopathic arthritis. Imaging and laboratory studies may be used to support a diagnosis of JIA in a child who has symptoms of arthritis, and to help rule out other underlying causes. Lab tests may reveal elevated inflammatory markers and anemia, as well as certain antibodies, including antinuclear antibody (ANA), rheumatoid factor (RF), and citric citrullinated peptide (CCP). Some children have JIA with no positive antibodies. To rule out infection, a doctor may order blood or joint fluid tests for Lyme disease antibodies or those of other conditions. Imaging studies such as X-ray, ultrasound and MRI, may be ordered to look for inflammation and damage to the joints. All children with a suspected diagnosis of JIA should be seen by an ophthalmologist to rule out uveitis.
The main goals of treating arthritis are to decrease joint pain and stiffness, control inflammation, and maximize growth and function. Treatment depends on the type and severity of the arthritis in addition to factors specific to the child and family. Medications that may be used include NSAIDs (nonsteroidal anti-inflammatory drugs), disease-modifying antirheumatic drugs (DMARDs), biologic medications, and injection of steroids directly into the affected joint(s). Physical and occupational therapy are crucial for restoring mobility and joint function. Children with JIA have the best prognosis when they have a multidisciplinary healthcare team that includes their parents, teachers, pediatric rheumatologist, ophthalmologist, and physical and occupational therapists.