Most people with adult Still disease have a combination of the following symptoms:

• Fever. Fever may rise to at least 102 degrees Fahrenheit (38.9 degrees Celsius). The fever may spike once or twice a day for a week or longer.
• Rash. A rash might come and go with the fever. The rash usually appears on the trunk, arms or legs.
• Sore throat. This is one of the first symptoms of adult Still disease. The lymph nodes in the neck might be swollen and tender.
• Achy and swollen joints. Joints — especially in the knees and wrists— might be stiff, painful and inflamed. Ankles, elbows, hands and shoulders also might ache. The joint discomfort usually lasts at least two weeks.
• Muscle pain. Muscular pain usually comes and goes with the fever. The pain can be severe enough to disrupt daily activities.

Symptoms of this disorder can differ from person to person. They can mimic those of other conditions, including lupus and a type of cancer called lymphoma.

When to see a doctor

If you have a high fever, rash and achy joints, see your health care provider. Also, if you have adult Still disease and develop a cough, difficulty breathing, chest pain or any other symptoms that are not usual, call your health care provider.

The cause of adult Still disease is not known. Some researchers suspect it might be triggered by a viral or bacterial infection.

Age is the main risk factor for adult Still disease. It is most likely to occur in adults between the ages of 15 and 25 and between the ages of 36 and 46. Males and females are equally at risk.

Adult Still disease inflames the organs and joints. Most complications from the disease result from this inflammation.

• Joint destruction. The chronic swelling and irritation that occurs with adult Still disease can damage the joints. The most commonly involved joints are the knees and wrists. Sometimes other joints, including the neck, foot, finger and hip joints, also are affected.
• Inflammation of the heart. Adult Still disease can inflame the saclike covering of the heart, called the pericardium. This results in inflammation of the pericardium, called pericarditis. The disease can also inflame the muscular part of the heart, called the myocardium. This results in inflammation of the myocardium, called myocarditis.
• Excess fluid around the lungs. Inflammation may cause fluid to build up around the lungs. When this happens, it can be hard to take deep breaths.
• Macrophage activation syndrome. This is a rare but serious complication of adult Still disease. It happens when the immune system goes into overdrive and potentially harms organs such as the heart, liver, spleen and kidneys.

No single test identifies adult Still disease. Imaging tests can reveal damage caused by the disease. Blood tests can help rule out other conditions that have similar symptoms.

A variety of medicines are used to treat adult Still disease. The type of medicine depends on how bad the symptoms are and possible side effects.

• Nonsteroidal anti-inflammatory drugs (NSAIDs). Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve), may help with mild joint pain and inflammation. Stronger NSAIDs are available by prescription. Since NSAIDs can damage the liver, regular blood tests may be needed to check liver function.
• Steroids. Many people who have adult Still disease require treatment with steroids, such as prednisone. These powerful drugs reduce inflammation. They may lower the body's resistance to infections and increase the risk of developing osteoporosis and diabetes.
• Methotrexate. The medicine methotrexate (Trexall) is often used in combination with prednisone. The prednisone dose is reduced when combined with methotrexate.
• Biologic response modifiers. If other medicines haven't worked, your health care provider may recommend a biologic response modifier. Biologic response modifiers are medicines that block proteins causing inflammation. These medicines are often referred to as biologics. Anakinra (Kineret), canakinumab (Ilaris) and tocilizumab (Actemra) are some biologics that are used to treat adult Still disease. Other biologics that may be helpful for treating adult Still disease include etanercept (Enbrel), infliximab (Remicade), adalimumab (Humira) and rituximab (Rituxan).

Here are ways to make the most of your health if you have adult Still disease:

• Understand your medicines. Even if you have no symptoms some days, it's important to take your medicines as your care provider recommends. Controlling inflammation helps reduce the risk of complications.
• Supplement your diet. If you're taking high doses of prednisone, talk to your care provider about taking more calcium and vitamin D supplements to help prevent osteoporosis.
• Keep moving. Although you might not want to work out if your joints ache, exercise is recommended for all types of arthritis. Exercise can help you keep your range of motion and relieve pain and stiffness.

You're likely to seek advice from your primary care provider, but you may receive a referral to a rheumatologist. A rheumatologist is a doctor who specializes in joint diseases.

Here's some information to help you get ready for your appointment.

What you can do

When you make the appointment, ask if there's anything you need to do in advance, such as fast for a specific test. Make a list of:

• Your symptoms, including when they started and how often they flare.
• Key medical information, including any other diagnosed health conditions.
• All medicines, vitamins and supplements you take, including the doses.
• Questions to ask your doctor.

Take a family member or friend along, if possible, to help you remember the information you get.

For adult Still disease, basic questions to ask your doctor include:

• What's likely causing my symptoms?
• What are other possible causes?
• What tests do I need?
• Is my condition likely temporary or chronic?
• What's the best course of action?
• What are the alternatives to the approach you're suggesting?
• I have these other health conditions. How can I best manage them together?
• Are there restrictions I need to follow?
• Should I see a specialist?
• Are there brochures or other printed material I can have? What websites do you recommend?

Don't hesitate to ask other questions.

What to expect from your doctor

Your health care provider is likely to ask you questions, such as:

• When did your symptoms begin?
• Do your symptoms come and go, or are they continuous?
• When are your symptoms most likely to flare?
• What treatments or self-care measures have you tried?
• Have any treatments or self-care measures helped?
• Have you been diagnosed with any other medical conditions?