Systemic juvenile idiopathic arthritis, known more commonly as SJIA, is the childhood form of a systemic autoinflammatory disease called Still's disease. In adults, this disease is called adult-onset Still’s disease (AOSD).
SJIA is a rare type of arthritis that causes inflammation in young people. It is called systemic because it can affect many parts of the body; juvenile because it most commonly affects young children (but also adolescents); and idiopathic because its cause is not yet known.1
The symptoms of SJIA can develop any time during childhood, but most commonly start at about two years of age. Up to 30% of children with SJIA still experience symptoms 10 years after their first symptoms. There is no cure for SJIA, but its symptoms and long-term complications can be controlled over time with treatment.1, 2, 3, 4
The cause of SJIA is still unknown, but it has been suggested that certain children have a genetic disposition, which is then triggered by something in their environment such as an infection.1 New theories suggest there may be several factors working together that cause SJIA to develop.10
In Europe it is estimated that less than one child per 100,000 develops SJIA each year.10 It is calculated that between 5 and 15 people in every 100,000 currently have SJIA.11,12,1
SJIA affects boys and girls equally worldwide.6
The symptoms of SJIA come and go in short-term flares. These are the first and most common symptoms of SJIA and often cause:1,5,6,7
If SJIA is poorly controlled, it can cause painful and lasting damage to various parts of the body and seriously affect a child’s quality of life. The earlier SJIA is recognized and treated, the better the outcome is likely to be.
The prognosis for children with SJIA is that they are more likely to develop heart and lung problems. Any breathing or heart-related concerns should be raised with a doctor as soon as possible.1,5 SJIA can also interfere with normal bone growth. This can lead to one limb growing longer than another or overall stunted growth.1
Possible symptoms of SJIA 5,6,7
In terms of life expectancy, SJIA has also been associated with serious health complications including macrophage activation syndrome (MAS) and amyloidosis. MAS is a serious complication of rheumatic diseases (conditions that affect the joints) caused by activation and uncontrolled multiplication of an immune cell called macrophages. It occurs in about 5-8% of children with SJIA and it can lead to life-threatening systemic symptoms and internal organ failure.5,6,8 Amyloidosis is a condition in which there is an abnormal build-up of a protein called amyloid in the kidneys that can lead to kidney failure. Improved diagnostics and treatment options mean that kidney damage caused by amyloidosis occurs less frequently than in the past.5,9
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Life with a rare autoinflammatory disease like SJIA can be different from patient to patient. Children with SJIA typically experience symptom flares, with some having healthy periods between. The severity of the symptoms varies.3,14,15 Some can experience a monocyclic disease course, in which they recover completely after a number of years. Others might experience recurrent episodes with periods of remission in between. While some people will experience persistent symptoms.
Possible disease courses of SJIA 3,14,15
If your child is displaying any of the symptoms of SJIA, it is important you speak to your doctor as soon as possible and obtain an accurate diagnosis. Click here for guidance on finding a specialist pediatric doctor and what you need to know to prepare for your first appointment with an SJIA expert.
The challenges of living with SJIA are many, and not simply physical. Not being able to do many of the simple, everyday things people take for granted, the disease takes an emotional and mental toll on everyone affected by SJIA – parents and family, as well as the child dealing with this autoinflammatory condition themselves.
Correct diagnosis of SJIA has improved greatly in recent years. Most often, children presenting with symptoms of SJIA to their family doctor will be referred to a pediatric rheumatologist. Knowledgeable in autoinflammatory diseases, this specialist doctor is best placed to diagnose SJIA.
In addition to assessing a child’s symptoms (e.g. high fever for at least two weeks, joint pain and inflammation for at least six weeks), the rheumatologist will conduct a comprehensive physical exam. X-rays or ultrasound are often used to detect joint, lung or heart inflammation, while a blood test may be necessary to diagnose SJIA.1
Living with a rare autoinflammatory disease is different from one person to the next. Watch this series of videos below to find out how patients and their families share their experiences of living with SJIA, FMF and other autoinflammatory conditions.
Download our eBook I’m Rare or Living with Recurrent Fever eBook to learn more from the experiences of others diagnosed with SJIA and a what it means to live with a rare periodic fever syndrome like SJIA
It can be uncomfortable learning that your child has an incurable disease like SJIA. For them it will mean limitations in their day-to-day activities, disruption to their overall development and upset to their emotional wellbeing and quality of life. Find more information and advice on the day-to-day management of SJIA here or follow the inspiring stories of other children and their families here.
There is no cure for SJIA, but there are treatments which can reduce the severity of the symptoms and even make remission possible.1 Doctors are so much better equipped to help people with SJIA than they were 20 years ago.
Exercise is an important part of the SJIA treatment process, as it will help build muscle strength, increase energy and reduce pain.
Good communication with doctors and specialists will help provide a better understanding of the diagnosis and the treatment options available.
Making sure your child maintains a healthy diet is even more important when they have been diagnosed with SJIA.
Some children affected by SJIA may experience a suppressed appetite, especially during flares. This could be as a result of the disease itself or perhaps a side-effect of a medication they are taking. When a child feels sick and is experiencing symptoms such as joint pain, fatigue, fever or stomach pain, they may find eating difficult. It could also be physically difficult for them to eat, as arthritis in their hands may make using utensils much harder.
Sometimes, though, medications could increase their appetite, meaning they feel hungry a lot of the time and perhaps eat more unhealthy food than they should.1
All this can make it hard to ensure your child is getting all of the nutrients they need in order to grow and be healthy. But there are steps you can take to make food less of a struggle for you and your child. A dietician or nutritional expert can work with you and your child to figure out ways to combat any food-related issues. This could be through behavioural changes such as altering mealtime routines, or it could be through dietary changes and suggestions on types of food to buy and cook.
It could also involve working with the dietician to educate your child about their diet and why it’s important to eat certain foods and get the nutrients they need to help their body grow strong and ready to deal with their flares.
There is currently no evidence to support a special diet for children with SJIA and simply following a balanced diet is recommended. But there has been research into foods which may have a beneficial effect on arthritis symptoms, through fighting inflammation, strengthening bones and supporting the immune system:
These are just some suggestions, but simply doing what you can to help them keep a balanced diet and ensuring that they are receiving the right medical treatment are the most important ways to help them stay healthy with their condition.
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