What is Juvenile Arthritis?
Juvenile arthritis is an umbrella term used to describe the many autoimmune and inflammatory conditions that can develop in children ages 16 and younger. Juvenile arthritis is an autoimmune disease. That means the immune system attacks the body itself. 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. Researchers believe juvenile arthritis may be related to genetics, certain infections, and environmental triggers.
There are no known causes for most forms of juvenile arthritis, nor is there evidence to suggest that toxins, foods or allergies cause children to develop the disease. Some research points toward a genetic predisposition, which means the combination of genes a child receives from family members may cause the onset of arthritis when triggered by other factors.
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
The three types of juvenile arthritis are oligoarticular, polyarticular, and systemic.
In Oligoarticular, 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. 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 often have a more severe form of the disease.
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.
