The first signs of juvenile rheumatoid arthritis can sometimes be mistaken for the ordinary illnesses and injuries of childhood. In other children the signs may be quite obviously those of arthritis.
Symptoms may include:
- High fevers that tend to spike in the evening and then suddenly disappear
- Limping or a sore wrist, finger or knee
- Rashes that suddenly appear and disappear in one or more areas
- Stiffness in the neck, hips or other joints
- Joint stiffness that is worse after rest
- Sudden swelling of the joints, which stay enlarged. These joints may appear reddened and feel warm.
It is important for parents and teachers to understand that the symptoms of juvenile rheumatoid arthritis vary from child to child and even from day to day in the same child.
Many rheumatologists (doctors specializing in joint disorders) find that the greater the number of joints affected, the more severe the disease and the less likely that the symptoms will eventually go away.
There are three main types of juvenile rheumatoid arthritis:
- Polyarticular arthritis, which involves pain or swelling in five or more joints. This type of juvenile rheumatoid arthritis affects more girls than boys. It affects small joints such as those in the hands as well as weight-bearing joints such as the knees, hips, ankles, feet, and neck.
- Pauciarticular juvenile rheumatoid arthritis, affects four or fewer joints. It most commonly affects the knee and wrist joints. An inflammation of the iris (the colored area of the eye) may occur with or without active joint symptoms. This inflammation, called iridocyclitis, iritis or uveitis, can be detected early by an ophthalmologist.
- Systemic juvenile rheumatoid arthritis affects the whole body. This will cause a child to have the most and most severe symptoms. The spleen and lymph nodes may also become enlarged. Eventually many of the body's joints are affected by swelling, pain, and stiffness.
Causes and Risk Factors
It is not yet known what causes rheumatoid arthritis in children. It is an autoimmune disease. In this type of disease, the white blood cells lose their ability to tell the difference between the body's own healthy cells and harmful invaders like bacteria or viruses. The immune system releases chemicals that damage healthy tissues, causing swelling and pain.
Usually the symptoms of juvenile rheumatoid arthritis appear between the ages of six months and 16 years.