Juvenile rheumatoid arthritis (JRA) is a childhood disease that affects the joints. There are several different types of JRA, but systemic-onset juvenile rheumatoid arthritis is the rarest form, accounting for just 10%-20% of all JRA cases.
Systemic-onset JRA causes high, spiking fevers, rash, and joint aches. The word "systemic" means that it affects the entire body. Systemic-onset JRA usually begins when a child is between 5 and 10 years old, and it affects boys and girls equally.
Systemic-onset JRA is also known as Still's disease, named after the English doctor Sir George F. Still, who first recognized the illness in children in the late 1800s.
No one really knows what causes systemic-onset JRA. It is believed to be caused by a faulty immune response. That response may be triggered by another factor, such as stress, or a viral or bacterial infection.
Symptoms of Systemic-Onset JRA
The hallmark signs of systemic-onset JRA are a very high fevers (102 degrees Fahrenheit or higher) and a pale pink or salmon-colored rash, usually on the child's chest and thighs. Because of these symptoms, systemic-onset JRA is sometimes confused with a bacterial infection, but systemic-onset JRA does not respond to antibiotic treatment.
The fever from systemic-onset JRA tends to spike several times during the day, usually peaking at night and then improving in the morning. Children also have joint pain and/or swelling, which can become more painful when the fever peaks.
Symptoms come and go over days, weeks, or months. When the fever is low, the child will seem to be fine, but when the fever returns the child will look and act sick. Children can have "good" days with few or no symptoms, and "bad" days with flare-ups of more severe symptoms.
Systemic-onset JRA also can cause inflammation of the lining of the lung (pleuritis) or lining of the heart (pericarditis), swollen lymph nodes, and an enlarged spleen and liver. Children with the condition may grow more slowly than normal.