Doctor's Notes on Juvenile Idiopathic Arthritis
(Juvenile Rheumatoid Arthritis)
Juvenile idiopathic arthritis (formerly referred to as juvenile rheumatoid arthritis, or JRA) refers to a group of disease characterized by chronic joint inflammation that initially affected a child before 16 years of age. Juvenile idiopathic arthritis (JIA) includes the five main forms of childhood arthritis: pauciarticular, polyarticular, systemic, enthesitis-related, and psoriatic arthritis.
The most common symptoms of juvenile idiopathic arthritis include joint pain, warmth, stiffness, and swelling that may be more severe in the morning. Other symptoms of JIA include loss of joint function and reduced range of motion, limping, joint deformity, eye irritation/pain/redness (uveitis or iritis), eye sensitivity to light, recurrent fevers that may “spike” several times in one day, salmon-colored rash, psoriasis rash in those with the psoriatic form of JIA, muscle aches similar to aches that accompany the flu, lymph node swelling (“swollen glands”), weight loss, and growth problems.
Juvenile Idiopathic Arthritis
(Juvenile Rheumatoid Arthritis) Symptoms
The symptoms of juvenile idiopathic arthritis vary greatly from child to child. They may be very mild, very severe, or anything in between, and they may change over time, sometimes overnight. Fluctuations of symptoms, whereby they get worse (flare) and then get better or go away completely and resolve (remission), are fairly typical of JRA.
- Joint pain, warmth, stiffness, and swelling: These are the most common symptoms of JIA, but many children do not recognize, or do not report, pain. Stiffness and swelling are likely to be more severe in the morning.
- Loss of joint function: Pain, swelling, and stiffness may impair joint function and reduce range of motion. Some children are able to compensate in other ways and display little, if any, disability. Severe limitations in motion lead to weakness and decreased physical function.
- Limp: A limp may indicate a particularly severe case of JIA, although it also may be due to other problems that have nothing to do with arthritis, such as an injury. In JIA, a limp often signals knee involvement.
- Joint deformity: The joints may grow in an abnormal, asymmetrical way, causing deformities of the extremity involved.
- Eye irritation, pain, and redness: These symptoms are signs of eye inflammation. The eyes may be sensitive to light. In many children with JIA, however, eye inflammation has no symptoms. If the inflammation is very severe and not reversed, it can cause loss of vision. The most common types of eye inflammation in JIA are uveitis and iritis. The names refer to the part of the eye that is inflamed, the uvea and iris, respectively.
- Recurrent fevers: Fever is high and comes and goes with no apparent cause. Fever may "spike" (go high) as often as several times in one day.
- Rash: A faint, salmon-colored rash may come and go without explanation. Psoriasis rash in those with the psoriatic form of JIA.
- Myalgia (muscle aches): This is similar to that achy feeling that comes with the flu. It usually affects muscles throughout the whole body, not just one part.
- Lymph node swelling: This is sometimes called "swollen glands," but the lymph nodes are not glands. They are small nodules of tissue that work as part of the immune system to help remove certain types of dead cells. Normally, lymph nodes are very small and cannot be felt through the skin. When swollen, they can be felt and often are tender to the touch. Lymph nodes are spread throughout the body, but swollen lymph nodes are noticed most often in the neck and under the jaw, above the collarbone, in the armpits, or in the groin.
- Weight loss: This is common in children with JIA. It may be due to the child's simply not feeling like eating. Weight loss with diarrhea suggests possible inflammation of the digestive tract.
- Growth problems: Children with JIA often grow more slowly than average. Growth may be unusually fast or slow in an affected joint, causing one arm or leg to be longer than the other. General growth abnormalities may be related to having a chronic inflammatory condition such as JIA or to the treatment, especially glucocorticoids (for example, prednisone).
Juvenile Idiopathic Arthritis
(Juvenile Rheumatoid Arthritis) Causes
The cause of juvenile idiopathic arthritis is unknown. Like adult-type RA and many other related diseases, JIA is an autoimmune disease. This means that the body's immune system mistakenly attacks the tissues it is supposed to protect.
- The chronic inflammation of the synovium (the fluid-producing tissue that surrounds the joints) is linked to greater-than-normal activity of the immune system.
- Normally, the immune system fights "assaults" by "invaders" such as infections or blood or tissue from another person.
- The immune system produces specialized cells and proteins, which are released into the bloodstream to fight off the "invaders." One important type of immune protein is called an antibody.
- In autoimmune diseases such as JIA, the cells and antibodies of the immune system attack the body's own tissues. In the case of arthritis, the attack is directed against the synovium, which becomes inflamed.
- The inflammation causes the synovium to thicken and grow abnormally. As the synovium expands outside of the joint, it presses on and eventually damages the bone and cartilage of the joint and the surrounding tissues such as ligaments and tendons.
- We do not know what causes the inappropriate autoimmune response. Because the cause has not yet been discovered, we use the term "idiopathic" which means "of unknown cause."
- Emotional factors and diet do not appear to be risk factors for JIA.
- According to statistics from the Arthritis Foundation, there are at least 300,000 children in the U.S. with JIA.
Rheumatoid arthritis (RA) is an autoimmune disease where the body attacks the lining tissue of joints, causing chronic joint inflammation. While it primarily affects joints, it can also cause inflammation of organs, such as the lungs, eyes, skin, and heart.
People with RA may experience an increase in symptoms –called flares – that can last for days or weeks. They may also have periods of remission where they have few or no symptoms. There is no cure for rheumatoid arthritis, but medications can stop the progression of the disease and ease symptoms.
Rheumatoid Arthritis : What is Rheumatoid Arthritis? QuizQuestion
The term arthritis refers to stiffness in the joints.See Answer
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.