Systemic juvenile idiopathic arthritis (SJIA) factsheet


Systemic juvenile idiopathic arthritis (SJIA) is a rare, severe type of juvenile idiopathic arthritis (JIA).

JIA is a group of conditions that cause your child’s joints to become inflamed or swollen. 

SJIA affects body tissue and organs, along with the joints. It is an autoinflammatory condition. This means inflammation can happen throughout the body for no reason, rather than in response to illness or injury. 

SJIA is the least common type of JIA. It usually develops around two years of age but can happen at any time during childhood. SJIA is a life-long condition and can continue into adulthood.

 Signs and symptoms

Children with SJIA will have symptoms of JIA, including:

  • pain or tenderness in the joints
  • swelling and stiffness in the joints
  • redness, rashes and warmth in the joints and the skin
  • tiredness and an unusual lack of energy
  • loss of appetite
  • generally feeling unwell
  • high, unexplained fever.

They may also have:

  • swollen glands
  • severe inflammation in other organs, including the heart and lungs
  • severe inflammation of the tissue around the heart and lungs
  • swelling of the liver and spleen.


Your local doctor will refer your child to a specialist doctor called a rheumatologist for diagnosis and management of SJIA. A rheumatologist looks after the joints and muscles.

There is no single test for SJIA, and it can be difficult to diagnose. Your child’s doctor may need to rule out other causes of symptoms by:

  • taking a detailed family and medical history
  • physically checking your child's joints and organs
  • checking the results of blood tests
  • checking the results of scans and x-rays of the joints, body tissue and organs.


Generally, SJIA responds well to treatment and careful management. 

This involves:

  • medication to reduce inflammation
  • preventing any long-term damage to joints, body tissue and organs
  • improving your child’s ability to move and do their everyday activities.

SJIA is a long-term illness, but it can get better and go into remission as your child grows.

Remission means the disease does not cause any symptoms for a period but may flare up from time to time.

Last updated Wednesday 17th April 2024


This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.

© Sydney Children’s Hospitals Network 2024