Juvenile rheumatoid arthritis (JRA) is a disease of the joints in children. It can effect a child over a long period of time. JRA often starts before the child is 16 years old.

In JRA, the joint to become red and swollen. It will make the joint painful and difficult to move. JRA can also lead to long term damage to the joint. For some, JRA can interfere with the child's growth and development.

There are five major types of JRA:

  • Pauciarticular JRA—four or less joints are affected in the first 6 months of illness
  • Polyarticular JRA—five or more joints are affected in the first 6 months of illness
  • Enthesitis associated arthritis—there is also swelling of the tendon at the bone
  • Psoriatic arthritis—associated with a skin disease called psoriasis
  • Systemic onset JRA (also called Still’s disease)—affects the entire body, least common type of JRA

Rheumatoid Arthritis
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JRA is caused by a problem of the immune system. The normal job of the immune system is to find and destroy items that should not be in the body, like viruses. With JRA, the immune system attacks the healthy tissue in the joint. It is not clear why this happens. The immune system problems may be caused by genetics and/or factors in the environment.