context: Adult-onset Still's disease is an inflammatory disease that may affect many joints, internal organs, and other parts of the body. Adult Still's develops most often in people before age 45, but can first occur in later years as well. The cause of Still's is unknown and there are no known risk factors. It is thought that a virus or other type of infectious agent may trigger Still's disease, but there is no proof. Although some features are similar, adult-onset Still's disease is different than Still's in children. In children, Still's disease is considered a form of juvenile rheumatoid arthritis and referred to as systemic-onset juvenile rheumatoid arthritis. Less than one in 100,000 people develop adult-onset Still's each year and it is more common in women. Almost all people with adult-onset Still's disease have fevers, joint pain, sore throat, and a rash. But the type, pattern, and severity of symptoms vary from person to person and even from month to month for the same person. For example, symptoms may come and go. And, at first you may have just a few symptoms, then later you may have more. These are common symptoms of adult Still's disease: A fever (equal to or greater than 102 degrees) that comes on quickly once per day, usually in the afternoon or evening. For most people, these fevers resolve without treatment. Joint pain, warmth, and swelling affecting a few joints at first -- often knees and wrists -- then several joints. Morning joint stiffness often lasts for several hours. A salmon pink-colored skin rashthat usually comes and goes with the fever and usually doesn't itch. Flat spots or both flat spots and small, raised bumps may appear on your torso, upper arms or legs, or face. Severe muscle aches, which also may ebb with the fever. A sore throatthat can be severe, constant, and burning. Other symptoms of adult-onset Still's may include: Abdominal pain and swelling Pain when taking a deep breath Swollen glands (lymph nodes) Unexplained weight loss Contact your doctor if you experience any of the symptoms of adult-onset Still's disease. If you've already been diagnosed and have breathing troubles, call your doctor right away. In addition to lung, liver, or heart inflammation, complications of Still's may include chronic arthritis in several joints. It can be difficult to diagnose Still's disease. That's because Still's has some similarities to other diseases, such as Lyme disease, Crohn's disease, and certain infections. Before confirming your diagnosis, your doctor will need to rule out other problems. A medical history and physical exam are often the first steps. You may need a variety of blood tests to check for inflammation, changes in blood cell counts, iron levels, and liver enzymes, for example. Imaging tests check for inflammation or enlargement of certain organs. If you have adult-onset Still's disease, you are more likely to have blood test results like these: A high white blood cell count and low red blood cell count High C-reactive protein High erythrocyte sedimentation rate ( ESR) Negative antinuclear antibodies Negative rheumatoid factor High liver enzymes High ferritin and fibrinogen You may have more than one imaging test, such as abdominal ultrasound or CT, or X-rays of joints, chest, or abdomen. These tests may check for the following: An inflamed heart lining (pericarditis) Fluid buildup in between the lining of the lungs and chest cavity (pleural effusion) An enlarged spleen, liver, or lymph nodes Joint inflammation or damage Once you've received a diagnosis, what can you expect? The course of the disease is difficult to predict. But these statistics may give you some idea of what may happen. 1 in 5 people have symptoms that go away and never come back. About 1 in 3 have symptoms that go away but come back several times over several years. These relapses are often less severe and shorter than the first episode. 1 in 2 people have symptoms that last a long time, with the disease sometimes affecting vital organs. It isn't yet possible to prevent Still's disease, and there is no cure. If you've been diagnosed, the goal is to control symptoms and the course of the disease. This can help prevent or lessen any complications. Early treatment for adult-onset Still's disease is aimed at controlling symptoms of arthritis with nonsteroidal anti-inflammatory drugs ( NSAIDs). NSAIDs include ibuprofen ( Advil, Motrin), naproxen ( Naprosyn, Aleve), and high-dose aspirin. These may begin even before your diagnosis is confirmed. Analgesics, or pain drugs, may also be prescribed. You may require these medications for some time. If so, your doctor will likely monitor your liver function and watch for other side effects. With a firm diagnosis of adult-onset Still's disease, you may require corticosteroids, such as prednisone, if your disease is severe or doesn't respond to NSAIDs. Corticosteroids are used for systemic disease that affects several parts of the body. Because of potential serious side effects, though, you can't use them for a very long time. If you have a chronic case of Still's, you may need medications to suppress your immune system and to control arthritis and other symptoms. You may take more than one medication at the same time and you may need to take these for a long time. You take some medications by mouth and others by injection. These are examples of medications your doctor may prescribe: Anakinra ( Kineret) Antitumor necrosis factor therapies: adalimumab ( Humira), etanercept-szzs( Ereizi), etanercept ( Enbrel), infliximab ( Remicade), infliximab-dyyb ( Inflectra), a biosimilar Azathioprine ( Imuran) Cyclophosphamide ( Cytoxan) Cyclosporine ( Neoral) Hydroxychloroquine ( Plaquenil) Methotrexate ( Rheumatrex) Sulfasalazine ( Azulfidine) If adult-onset Still's disease affects your heart or lungs, your doctor may also need to prescribe medication to treat these problems. Ask your doctor if there are other steps you can take to manage your disease and feel better. For example, learn how to pace yourself and find ways to manage stress. Rest is important. This may help you minimize the number of "bad" days you have. Also, remember that this disease comes in cycles. Don't stop taking your medications during times when you're feeling better unless you've discussed this ahead of time with your doctor.