Adult Still disease, also called adult-onset Still disease (ASOD), is a rare condition. It can involve inflammatory arthritis, but it may affect other parts of the body too. Common symptoms are fever, rash and joint pain. The condition may happen in some people only once. Then it goes away and doesn't come back. In other people, Still disease doesn't go away, or it goes away but then comes back.

Adult Still disease can injure joints, especially the wrists and knees. Treatment includes medicine to ease pain and help control the disease. A corticosteroid medicine such as prednisone often is used if pain relievers such as ibuprofen (Advil, Motrin IB, others) are not enough.

Most people with adult Still disease have more than one of the following symptoms:

• Sore throat. This often is one of the first and most common symptoms of adult Still disease.
• Fever. Fever is typically high, rising above 102 degrees Fahrenheit (38.9 degrees Celsius). The fever often spikes once or twice a day for a week or longer.
• Rash. A rash might come and go with the fever. The rash usually shows up on the back, chest, belly, arms or legs.
• Painful joints. Joints may become achy, stiff and swollen, especially the wrists and knees. Ankles, elbows, hands, feet and shoulders also might ache. Joint pain often lasts at least two weeks.
• Muscle pain. Pain in the muscles typically comes and goes with the fever. Muscle pain sometimes may be so bad that it's hard to do daily activities.
• Swollen lymph nodes. Lymph nodes in the neck, armpits and groin may be swollen and tender.
• Belly pain. Adult Still disease may cause the liver and spleen to get larger. That can lead to pain in the upper part of the belly area.

The specific symptoms of adult Still disease may not be the same for everyone. The symptoms also can look like those of other conditions, including lupus and a type of cancer called lymphoma.

When to see a doctor

If you have a high fever, a rash that keeps coming back and swollen, painful joints, make an appointment to see a healthcare professional. If you have been diagnosed with adult Still disease and have a cough, breathing issues, chest pain or any new symptoms, contact your healthcare professional.

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

Age is the main risk factor for adult Still disease. It most often affects people between the ages of 15 and 25 and between the ages of 36 and 46.

Adult Still disease causes a type of swelling in the organs and joints called inflammation. Most health concerns that happen as a result of adult Still disease, called complications, are caused by the inflammation.

• Joint injury. The swelling and irritation that happens with adult Still disease can damage joints. The joints that are most often affected are the wrists and knees. Sometimes other joints, including those in the ankles, elbows, hands, feet and shoulders may be affected too.
• Swelling in and around the heart. Adult Still disease can cause swelling and inflammation of the saclike covering of the heart, called the pericardium. That condition is called pericarditis. The disease also can lead to inflammation in the muscle of the heart, called the myocardium. That condition is called myocarditis.
• Extra fluid around the lungs. Inflammation may cause fluid to build up around the lungs, a condition called pleural effusion. When this happens, it can be hard to take deep breaths.
• Injury to other organs. Adult Still disease can affect other organs, including the liver, spleen, pancreas, kidneys and lymph nodes.
• Macrophage activation syndrome. This is a very rare but serious health condition that can be triggered by adult Still disease. It happens when the immune system goes into overdrive. It may harm organs such as the heart, liver, spleen and kidneys.

No single test can diagnose adult Still disease. Symptoms can be used to help make a diagnosis. Imaging tests may show joint and organ injury that the disease can cause. In people who have adult Still disease, blood tests may show high levels of some markers of inflammation, including C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), also called sed rate. Blood tests also can help rule out other conditions that have similar symptoms, such as infections, cancers and other autoimmune conditions.

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

• Nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs such as ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve), may help with mild joint pain and swelling. Stronger NSAIDs are available by prescription. Because NSAIDs may harm the liver, you might need blood tests to check liver function on a regular basis.
• Corticosteroids. Many people who have adult Still disease need treatment with a corticosteroid, such as prednisone. These powerful medicines ease inflammation. But they may lower the body's resistance to infections, raise the risk of diabetes and lead to weak, brittle bones, a condition called osteoporosis.
• Methotrexate (Jylamvo, Trexall, Xatmep, others). The medicine methotrexate may be used along with prednisone. The prednisone dose typically is lowered when it's used with methotrexate.
• Biologic response modifiers. If other medicines haven't worked, your healthcare professional may suggest that you take a biologic response modifier. These are medicines that block proteins that cause inflammation. They often are called biologics. Some biologics used to treat adult Still disease include:
  • Adalimumab (Humira)
  • Anakinra (Kineret)
  • Canakinumab (Ilaris)
  • Etanercept (Enbrel)
  • Infliximab (Remicade)
  • Rilonacept (Arcalyst)
  • Tocilizumab (Actemra)

If you have adult Still disease, these steps can help keep you healthy:

• Take your medicines. Even if you don't have symptoms every day, it's important to always follow your healthcare professional's directions for taking your medicines. Doing so will help manage inflammation, and that lowers the risk of developing other health issues.
• Keep moving. You might not want to work out if your joints ache. But exercise can help you keep your range of motion and ease pain and stiffness.
• Ask about calcium and vitamin D. If you take a corticosteroid medicine, such as prednisone, talk with a member of your healthcare team about taking calcium and vitamin D supplements. They may help prevent osteoporosis, a disease that weakens bones.

You're likely to start by seeing your primary healthcare professional. But you might be referred to a doctor who is trained to treat joint diseases, called a rheumatologist. Here are some tips to get ready for your appointment.

What you can do

When you make the appointment, ask if there's anything you need to do before your appointment, such as not eating or drinking for a certain amount of time. Make a list of:

• Your symptoms, including any that don't seem related to the reason for your appointment.
• Key personal information, including major stresses, recent life changes and family medical history.
• All medicines, vitamins and other supplements you take, including the doses.
• Questions to ask your healthcare professional.

Take a family member, friend or another trusted person with you, if possible, to help you remember the information you're given.

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

• What's likely causing my symptoms?
• What are other possible causes?
• What tests do I need?
• Is my condition likely short-term or long-lasting?
• What's the best course of action?
• What are the alternatives to the approach you're suggesting?
• I have other health conditions. How can I best manage them together?
• Are there things I should or shouldn't do?
• Should I see a specialist?
• Are there brochures or other printed material I can have? What websites do you recommend?

Be sure to ask any other questions you may have.

What to expect from your doctor

Your healthcare professional is likely to ask you questions, such as:

• When did your symptoms start?
• Are your symptoms always present, or do they come and go?
• When are your symptoms most likely to flare?
• What, if anything, makes your symptoms better?
• What, if anything, makes your symptoms worse?
• Have you tried any treatments or self-care measures? Have any of them helped?
• Have you been diagnosed with any other medical conditions?