Adult Still's Disease: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Adult Still's Disease?
A rheumatologist, a doctor who treats joint and muscle inflammation, usually cares for people with adult Still's disease. The illness can affect many parts of the body, so other specialists may help. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is adult Still's disease?
Adult Still's disease is a rare illness that causes high fevers, rash, and joint pain. It may lead to long-term arthritis, which is swelling and pain in the joints. It is also called adult-onset Still's disease. It is the adult form of systemic juvenile idiopathic arthritis, a type of arthritis that occurs in children. It is an inflammatory disorder, which means the body swells and gets irritated.
Symptoms
Almost all people with the illness have fever, joint pain, sore throat, and a rash.
- The fever comes on quickly. It is often higher than 102.2 degrees F (39 degrees C). In some people it spikes once or twice a day, usually in the late afternoon or early evening.
- Joints may become painful, warm, swollen, and stiff. The knees, wrists, ankles, and hips are most often affected. Morning stiffness can last at least one hour.
- The rash is pink or salmon colored and comes and goes with the fever. It mostly affects the chest and thighs and fades quickly.
- Muscle pain can be intense and is often worse during fever episodes.
Other symptoms include a sore throat, swollen lymph nodes (the small glands that fight infection), abdominal pain and swelling, weight loss, and pain when taking a deep breath.
Symptoms follow three patterns. An episode may last weeks to months and not come back. In others, episodes come and go for years. Some people have symptoms that last.
Causes and who gets it
The cause is unknown. Researchers think it might come from a mix of genetic factors and a strong response to infections or other things in the environment. Some researchers think the illness is autoinflammatory. That means the body's first line of defense overreacts. It is not the same as autoimmune, where the immune system mistakenly attacks healthy tissue. Fewer than 1 out of 100,000 people develop it each year, and it affects women more often than men. It mainly affects young adults ages 16 to 35.
How doctors diagnose it
Diagnosis can be hard because there is no single test. Doctors rule out other illnesses first, such as infections and cancer. A complete blood count, which counts blood cells, may show high white blood cells and low red blood cells. Two markers of inflammation, C-reactive protein (CRP) and ESR (sedimentation rate), are higher than normal. Ferritin, a blood protein that stores iron, is often very high. Liver tests may show high levels of two liver enzymes, AST and ALT. Rheumatoid factor and ANA, two antibody tests, are usually negative. Imaging tests may include x-rays of the joints or chest and an abdominal ultrasound, which uses sound waves to make pictures of the belly.
Treatment
The goal of treatment is to control symptoms such as arthritis. Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, are most often used first. For more severe cases, doctors may use prednisone, a steroid medicine that fights inflammation. Long-term use of steroid medicines is linked to many side effects, so doctors lower the dose over time. Methotrexate, a medicine that calms the immune system, can help keep the steroid dose low. If those do not work, doctors may use biologic medicines that block parts of the immune system. The FDA has approved canakinumab (Ilaris) for active Still's disease. It blocks interleukin-1, a protein that drives inflammation. Anakinra blocks the same protein. Tocilizumab is approved for Still's disease in children and is widely used in adults.
When to see a doctor
Contact a doctor right away if you have a high fever with a rash and joint pain. If you have already been diagnosed, call your doctor right away if you develop a cough. A serious complication called macrophage activation syndrome makes the immune system overactive. It can be life threatening and causes high fevers, severe illness, and low blood cell counts. Call 911 if you have trouble breathing, chest pain, confusion, fainting, or bleeding that will not stop.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. This doctor can evaluate new symptoms and help coordinate your care with a rheumatologist. They can also follow your health over the long term if symptoms come back.
Common questions
Is adult Still's disease the same as juvenile arthritis?
It is the adult form of systemic juvenile idiopathic arthritis, a type of arthritis in children. Adults can have the same illness, but it is much less common.
What causes adult Still's disease?
Nobody knows the cause. Researchers think it might come from a mix of genetic factors and a strong response to infections or other things in the environment. It usually does not run in families.
What is the outlook for people with adult Still's disease?
In many people, symptoms may come back several times over the next few years. Symptoms last a long time in about one third of people. The illness is not usually life threatening.
Can it affect organs other than joints?
Yes. The spleen or liver may swell. Less often, the heart or lungs become inflamed, which can cause chest pain or trouble breathing.
Sources
- MedlinePlus - Adult Still disease
- National Organization for Rare Disorders - Adult-Onset Still's Disease
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
