A Common Misconception Is That Only The Old Can Get Arthritis
When most people think of arthritis they don't associate it with children. The most popular misconception about arthritis is that it is an old person's disease. In reality, arthritis affects people of all ages including over 285,000 American children.
What Is Juvenile Arthritis?
When people under the age of sixteen are affected by arthritis it is usually classified differently. The reason it is separately classified is because the course of the disease in children is usually different than it is in adults. Children experience different symptoms and generally have a more favorable prognosis.
Childhood arthritis is often referred to as JRA or juvenile rheumatoid arthritis, juvenile chronic arthritis, and Still's disease. These names are somewhat misnomers. Juvenile rheumatoid arthritis and adult onset rheumatoid arthritis differ in some characteristics but the names indicate strict similarity. Juvenile chronic arthritis is a misnomer since juvenile arthritis is not always chronic. Still's disease is a name which should be used for one very specific type of childhood arthritis.
Juvenile Arthritis Subsets
There are at least three main subsets of childhood arthritis, each affecting different joints with a distinct pattern of symptoms. The three major subsets are:
- polyarticular juvenile arthritis
- pauciarticular juvenile arthritis
- systemic juvenile arthritis (sometimes called Still's disease)
Juvenile Arthritis: Polyarticular Disease
Polyarticular disease is a disease of many joints. This type of juvenile rheumatoid arthritis affects more than five joints and is the type which is most similar to adult rheumatoid arthritis. Girls are two times more likely to have this disease than boys. The joints are usually affected symmetrically (on both sides). Often the small joints of the hands are affected, as well as other joints. Low grade fever, weight loss, and anemia may occur, and in severe cases growth problems.
Most children with polyarticular disease test negative for rheumatoid factor and their prognosis is usually good. A minority of children test positive for rheumatoid factor and seemingly are at more risk for chronic, progressive destruction and joint damage.
Juvenile Arthritis: Pauciarticular Disease
Pauciarticular disease is a disease of few joints. This type of juvenile rheumatoid arthritis affects four or fewer joints. Most commonly affected are the:
The joints are usually affected asymmetrically (one joint on one side). This is regarded as the most common type of JRA and affects over 50 percent of children with the disease. This type of juvenile rheumatoid arthritis affects mostly girls.
Children affected by pauciarticular disease usually have a positive antinuclear antibody (ANA) test and are prone to an inflammatory eye condition, iridocyclitis. Children with pauciarticular JRA generally do well.
Juvenile Arthritis: Systemic Disease
Systemic disease begins with generalized systemic symptoms which can affect internal organs and parts of the body other than joints. This form of juvenile rheumatoid arthritis is the least common and affects only about 10 percent of children with the disease. Systemic disease often begins with fevers which seem to come and go, lasting for weeks or months. A light-colored rash may exist on the thighs and chest. The child with systemic disease may exhibit:
- signs of enlargement of the spleen and lymph nodes
- inflammation of the heart muscle and surrounding tissues
- a high white blood cell count
- anemia
- fatigue
- weight loss
The prognosis of systemic disease is considered favorable. In 75 percent of cases, systemic disease subsides without long-term effects. In adults, this condition is called Adult Onset Still's Disease.
