A rare form of juvenile idiopathic arthritis (JIA) characterized by a high fever, a salmon-colored rash, and joint pain and inflammation. Still disease is also known as systemic, or systemic-onset, JIA. (Systemic JIA accounts for about 10% of all cases of JIA.) It most commonly begins in children aged 1&ndash6 but can also affect older children and even adults, in which case it is called adult-onset Still disease.
The first symptom of Still disease is usually a sudden fever that peaks (or “spikes”) once or twice a day. A salmon-colored rash that is either flat or bumpy often accompanies the fever spikes. Most people with Still disease also develop joint and muscle pain. Common sites of joint pain include the knees, wrists, ankles, and elbows.
To diagnose Still disease, doctors look at a person’s physical symptoms and may also take blood tests. Most people with Still disease have an elevated erythrocyte sedimentation rate (ESR or “sed rate”), a marker of inflammation in the blood, as well as an abnormally high white blood cell count. A low red blood cell count is also common. However, most people with Still disease test negative for the antibodies to rheumatoid factor (RF), a common marker of rheumatoid arthritis (RA). They also usually test negative for antinuclear antibodies (ANA), which are often present in the blood of people with other types of JRA as well as people with lupus.
The long-term prognosis for people with Still disease is variable. In some people Still disease goes away completely within one year. In others it seems to go away but then returns in periodic flares, which may be shorter and less severe than the first episode. And sometimes the condition can become chronic and last a lifetime. In these cases the fevers and rash may subside but the joint pain and inflammation persist. In severe cases, people with Still disease can also develop inflammation of the heart or lungs or cardiac tamponade (compression of the heart due to blood accumulating around the heart).
Still disease is initially treated with nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil, Motrin) and naproxen (Aleve, Naprosyn). Those who don’t respond to NSAIDs or have severe Still disease may need to be treated with corticosteroids such as prednisone, which reduce inflammation throughout the body. In other cases, doctors may prescribe disease-modifying antirheumatic drugs (DMARDs) such as methotrexate (Rheumatrex, Trexall) and/or biologic drugs such as etanercept (Enbrel).