Still’s Disease is a rare inflammatory disease that exists in two main forms: adult-onset Still’s disease (AOSD), and a type of childhood arthritis called systemic juvenile idiopathic arthritis (SJIA). Symptoms include fatigue, fever, joint pain, and inflammation.1,2
What is Still’s disease?
Both the adult form and the juvenile form of Still’s disease are marked by fatigue, fever, joint pain, and inflammation. A distinctive salmon-coloured rash is often present, and several of the body’s organs can be affected. SJIA, the form of the disease that affects children, can be associated with severe arthritis if not sufficiently controlled.3
Age of onset
- SJIA starts during childhood years, most commonly in the age range 0–5 years.4
- AOSD may begin at any age, most commonly in the age ranges of 15–25 years and 36–45 years.5
Different types of Still’s disease6,7
- The adult-onset version of Still’s disease is known as AOSD – adult-onset Still’s disease (or adult-onset Still disease).
- The juvenile-onset version of Still’s disease is known as SJIA – systemic juvenile idiopathic arthritis, or SO-JIA – systemic-onset juvenile idiopathic arthritis. These are two slightly different terms for the same disease.
- Other, more frequent, forms of JIA (juvenile idiopathic arthritis) exist besides SJIA (or SO-JIA). These other forms of JIA are not the same condition as Still’s disease.
How common is Still’s disease?
As with many rare diseases, it’s not possible to know for sure how many people have SJIA or AOSD, because of misdiagnosis or late diagnosis.
Some recent studies suggest that:
- AOSD affects 0.16–0.4 per 100,000 adults.8,9
- SJIA affects 3.5 per 100,000 children.10
Approximately the same number of males and females are affected, although some studies suggest that slightly more females are affected than males.11
What are the symptoms of Still’s disease?
The symptoms of AOSD and SJIA are much the same. Different people affected by AOSD or SJIA may experience the various symptoms in differing degrees.
The main symptoms of the condition include fatigue, muscle pain, sore throat, high fever reaching up to 41°C, a salmon-pink rash, and inflammatory arthritis which tends to be more severe in the juvenile form.12,13
How long does Still’s disease last?
For the juvenile form of the disease, up to 30% of children with SJIA still experience symptoms 10 years after their first symptoms.14 Symptoms can persist into adulthood.
AOSD generally follows one of three main patterns:
- Monophasic pattern: a single episode of symptoms that typically lasts weeks to months, but usually less than a year.
- Polyphasic (intermittent) pattern: more than one episode of symptoms. Patients usually remain free from symptoms for weeks to years between episodes.
- Chronic pattern: patients with chronic AOSD have persistent symptoms over time.15
Possible complications of Still’s disease16
People with Still’s disease can develop complications, especially if the condition is not correctly diagnosed and quickly treated.
Complications include:
- Joint damage and deformities resulting from uncontrolled arthritis
- Enlargement of the liver or spleen
- Macrophage activation syndrome (MAS) – a severe and life-threatening complication involving excessive activation of immune cells, leading to widespread inflammation, high fevers, organ dysfunction, and a drop in blood cell counts
- Pericarditis – inflammation of the sac surrounding the heart, leading to chest pain and potential cardiac complications
- Myocarditis – inflammation of the heart muscle, potentially resulting in chest pain, arrhythmias, and heart failure.
- Pleuritis – inflammation of the lining around the lungs, causing cause chest pain and difficulty breathing
- Amyloidosis (rarely) – deposits of abnormal proteins in various organs, which can affect their function
How is Still’s disease diagnosed?
Still’s disease can be difficult to diagnose because there is no one test that can definitively identify it.17 And because it is such a rare disease, many doctors won’t be familiar with it. This is a common problem with rare diseases. Diagnosis involves a process of exclusion.
Once AOSD or SJIA is suspected, the following tests may be used to confirm it: 18
- Thorough clinical evaluation
- Detailed patient history
- Various blood tests, for example to look for enzymes released by the liver
- Imaging to reveal changes in the bones or joints
- Scans to reveal enlargement of the spleen or liver
- Echocardiogram – a picture of the heart made by using sound waves19
Raising awareness of Still’s disease
- There is low awareness of Still’s disease20
- Low awareness may lead to diagnosis of other conditions first and therefore a treatment not targeting the actual disease.
- Delays in diagnosis are common. Still’s disease is often confused with infection.21
What treatments are available for Still’s disease?
There is no cure for Still’s disease but there are treatments. Thanks to recent developments, the outlook for people diagnosed with SJIA or AOSD is much better than it was even a few years ago.22
Treatments for SJIA in children23
The standard approach is to start with non-steroidal anti-inflammatory drugs (NSAIDs).
If NSAIDs don’t relieve the symptoms within a week, doctors might prescribe oral or intravenous corticosteroids. In high doses, these can quickly bring fever and other symptoms under control.
However, high doses of steroids can cause serious side effects in children if used over the long term. Once the symptoms are under control, doctors will gradually reduce the dose and eventually stop it completely. But not all patients respond well to corticosteroids, and some don’t tolerate this treatment.
In recent years, new medications have been approved that target specific inflammatory proteins. These drugs are known as biologics. They used to be considered a last resort, but some doctors now use them as a first-line therapy.
Once the systemic symptoms of SJIA have disappeared, nonbiologic, conventional disease-modifying anti-rheumatic drugs (DMARDs) may be used alone or with biologics for continued therapy to control arthritis. DMARDs may also slow joint damage.24
Treatments for AOSD in adults
The approach for treating AOSD is similar to that for SJIA: NSAIDs, DMARDs, steroids, and biological therapies.
Typically, NSAIDs will be the first-line treatment. In most adults, NSAIDs alone will not bring the condition fully under control. As for children with SJIA, doctors will prescribe steroids as one of the first treatments after NSAIDs for adults. Most adults will be prescribed steroids – but only for as short a period as possible, because of the side effects. Biologics may be prescribed as a longer-term treatment.
Besides medication, occupational therapy can be useful for those affected by AOSD over the long term. Occupational therapists can advise on how to get help with personal care and everyday physical activities that can be challenging for people with reduced mobility.25
Is Still’s disease hereditary?
Still’s disease is not hereditary and usually does not run in families. However, it is believed that some individuals may be born with a genetic predisposition that increases their risk of developing the disease.26 So, while genetics may be a factor, Still’s disease is classed as an idiopathic disease (a disease with unknown causes).
What causes Still’s disease?27,28
Still’s disease is believed to result from a combination of genetic, environmental, and immunological factors.
- Hormonal and environmental factors are believed to play a part.
- The disease may be triggered by viral infection or by allergic reactions.
- The exact cause or causes of AOSD of SJIA are still not fully understood.
- Ongoing research aims to uncover the specific genetic and environmental factors that contribute to its development
- Still’s disease involves the body's immune system responding inappropriately or mistakenly, leading to attacks on its own tissues or excessive inflammation.
- The condition is thought to be autoimmune or autoinflammatory.
What is the prognosis for Still’s disease?
The prognosis for a child diagnosed with SJIA can vary depending on several factors. These factors include how severely affected the individual is, the age at onset, the response to treatment, and whether there are any complications.29
SJIA: importance of early diagnosis
Early diagnosis and prompt, aggressive treatment can vastly improve the prognosis for individuals with SJIA. Advances in the understanding of the disease and the development of targeted therapies have led to better outcomes for many patients.30
AOSD prognosis: what to expect
Many people with AOSD can live a full and normal life with the right treatment. In some cases, the condition can resolve spontaneously. Usually, however, AOSD tends to affect people in one of three ways:31
Around one-third of people with AOSD:
- Will have it for less than a year before their symptoms ease. They might need to stay on treatment for some time to make sure the condition is completely under control.
- Will have flares of the condition before symptoms disappear completely. The flares can be years apart, and may not affect the joints. Symptoms may become easier to manage.
- Will develop long-term arthritis and may have flare ups quite frequently and for a long time.
How can people living with Still’s disease improve their lives?32
Lifestyle changes can help people with Still’s disease to manage their condition.
Exercise
Exercise is beneficial for managing Still's disease because it helps maintain joint flexibility, reduces stiffness, and improves overall physical and mental well-being, even during periods of active symptoms.
Diet
There is no known direct link between diet and Still’s disease. No specific food will help in preventing, curing or controlling Still's disease. However, being overweight can put extra strain on the joints, so it’s beneficial to keep to a healthy weight. Maintaining a balanced diet will help.
Managing fatigue
Fatigue is common in people who have Still’s disease, and pain can sometimes get in the way of things they need to do. They can benefit from learning how to pace themselves and protect their joints to help manage fatigue.
Sleep
Getting quality sleep is crucial for managing Still's disease as it supports the immune system, promotes healing, and helps reduce overall inflammation, contributing to better symptom management and overall well-being.33
Outlook – leading as near normal a life as possible
The long-term outlook for people with Still’s disease, and especially for children with SJIA, is vastly improved following the approval of biologic medications that target specific inflammatory proteins, including interleukin-1 and interleukin-6, which are overactive in the disease.34,35
Meet Vanda, a busy working mother in the UK living with AOSD. Discover how Vanda has risen to the challenges and embraced an active lifestyle, finding strength through support networks.
Vanda lives a very active lifestyle. Working as a busy civil servant and happily married with two children, she is also living with adult-onset Still´s disease (AOSD), a rare, auto-inflammatory condition.
Getting support
Support of friends, family, and counsellors is important for anyone living with AOSD or caring for child with SJIA. A number of organisations make resources and support available for individuals with Still’s disease and their families, including Versus Arthritis and the Arthritis Foundation.36,37
Related links
Explore the following resources to learn more about Still's disease. Discover valuable insights, expert advice, and supportive communities.
Immunology
The role of the immune system
References
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Apr, 2024