Fewer than 1 out of 100,000 people develop AOSD each year. It affects women more often than men.
The cause of adult Still disease is unknown. No risk factors for the disease have been identified.
Adult Still disease is a rare illness that causes high fevers, rash, and joint pain. It may lead to long-term (chronic) arthritis.
Still disease is a severe version of juvenile idiopathic arthritis (JIA), which occurs in children. Adults can have the same condition, although it is much less common. It is also called adult-onset Still disease (AOSD).
Exams and Tests
AOSD can only be diagnosed after many other diseases (such as infections and cancer) are ruled out. You may need many medical tests before a final diagnosis is made.
A physical exam may show a fever, rash, and arthritis. The health care provider will use a stethoscope to listen for changes in the sound of your heart or lungs.
The following blood tests can be helpful in diagnosing adult Still disease:
- Complete blood count (CBC), may show a high number of white blood cells and reduced number of red blood cells.
- C-reactive protein (CRP), a measure of inflammation, will be higher than normal.
- ESR (sedimentation rate), a measure of inflammation, will be higher than normal.
- Ferritin level will be very high.
- Fibrinogen level will be high.
- Liver function tests will show high levels of AST and ALT.
- Rheumatoid factor and ANA test will be negative.
Other tests may be needed to check for inflammation of the joints, chest, liver, and spleen:
In many people, symptoms may come back several times over the next few years.
Symptoms continue for a long time (chronic) in about one third of people with adult Still disease.
A rare form of the disease, called macrophage activation syndrome, can be very severe with high fevers, severe illness and low blood cell counts. The bone marrow is involved and biopsy is needed to make the diagnosis.
Other complications may include:
There is no known prevention.
Almost all people with the disease will have fever, joint pain, sore throat, and a rash.
- Joint pain, warmth, and swelling are common. Most often, several joints are involved at the same time. Often, people with the condition have morning stiffness of joints that lasts for several hours.
- The fever comes on quickly once per day, most commonly in the afternoon or evening.
- The skin rash is often salmon-pink colored and comes and goes with the fever.
Additional symptoms include:
- Abdominal pain and swelling
- Pain when taking a deep breath (pleurisy)
- Sore throat
- Swollen lymph nodes (glands)
- Weight loss
The spleen or liver may become swollen. Lung and heart inflammation may also occur.
The goal of treatment for adult Still disease is to control the symptoms of arthritis. Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, are most often used first.
Prednisone may be used for more severe cases.
If the disease persists for a long time (becomes chronic), medicines that suppress the immune system might be needed. Such medicines include:
- Anakinra (interleukin-1 receptor agonist)
- Tocilizumab (interleukin 6 inhibitor)
- Tumor necrosis factor (TNF) antagonists such as etanercept (Enbrel)
When to Contact a Medical Professional
Alonso ER, Olivé A. Adult-onset still disease. In: Hochberg MC, Silman AJ, Smolen JS, Weinblatt ME, Weisman MH, eds. Rheumatology. 6th ed. Philadelphia, PA: Elsevier Mosby; 2015:chap 87.
Gerfaud-Valentin M, Maucort-Boulch D, Hot A, et al. Adult-onset still disease: manifestations, treatment, outcome, and prognostic factors in 57 patients. Medicine (Baltimore). 2014;93(2):91-99. PMID: 24646465
Lee LA, Werth VP. Skin and rheumatic diseases. In: Firestein GS, Budd RC, Gabriel SE, McInnes IB, O'Dell JR, eds. Kelley and Firestein's Textbook of Rheumatology. 10th ed. Philadelphia, PA: Elsevier; 2017:chap 43.
National Organization for Rare Disorders. Rare diseases.org Web site. Adult onset Still's disease.