Systemic Juvenile Idiopathic Arthritis (sJIA) Fact Sheet

This article presents an overview of the most serious type of childhood arthritis, systemic juvenile idiopathic arthritis, and discusses the symptoms, prognosis and various treatment options.


What is Systemic Juvenile Idiopathic Arthritis (sJIA)?

Juvenile idiopathic arthritis (JIA) is a group of conditions characterised by chronic arthritis in children. Systemic JIA is the subset of JIA with the worst long-term prognosis and is the most serious type of childhood arthritis.

Facts and figures

  • It is estimated that JIA develops in about a thousand children in the UK every year; its cause isn't fully understood at present but it's thought to be an autoimmune disease
  • Systemic JIA is a type of JIA with the worst long-term prognosis, representing 10-20% of all juvenile idiopathic arthritides
  • Systemic JIA affects up to 2,500 children under 16 in the UK
  • Systemic JIA begins in children aged 16 years or younger
  • The peak age of onset is between 18 months and two years
  • One-half to two-thirds of patients develop a chronic persistent polyarthritis and approximately half of these children are left with significant disability
  • It occurs in equal frequency between boys and girls

What are the signs and symptoms of systemic JIA?

The main symptoms of JIA are swollen, painful and stiff joints. Additionally, systemic JIA has more severe symptoms, including:

  • fever
  • rash
  • tiredness and lack of energy
  • swollen glands
  • weight loss

Other characteristics of systemic JIA may include anaemia, enlargement of the liver and/or spleen, inflammation of the lining of the heart and/or lungs4 and stunted growth.

What is the burden of systemic JIA?

The only data available, for JIA, suggest the disease imposes a significant burden on different spheres of the patients', caregivers' and family's life. It also imposes a societal burden of significant health care costs and utilisation, affecting quality of life, physical function and visual outcome of children and impacts functioning in school and home.

What is the prognosis for systemic JIA?

Some children may be free of disease within two to four years, whereas others experience a relapsing course with both systemic and arthritic symptoms; the remaining patients can have persistent arthritis. 

How is systemic JIA diagnosed?

No specific laboratory test can diagnose sJIA, but blood tests check for the presence of autoantibodies and haemoglobin levels, and X-rays, MRI, CT or ultrasound scan may be used to check for any signs of inflammation in the joints or fluid build-up around the heart or lungs. 

What treatment options are available?

Mild forms of disease are usually treated with non-steroidal anti-inflammatory drugs such as ibuprofen. High dose corticosteroids are used to control systemic symptoms, but do not improve the long-term prognosis and can cause severe side effects. Treatment with traditional arthritis medications such as methotrexate is of little benefit and only 30 percent of children may respond to anti-tumour necrosis factor (TNF) therapy.

A reduced level of haemoglobin, which carries oxygen in the blood. Anaemia causes tiredness, breathlessness and abnormally pale skin. Full medical glossary
Any drug that suppresses inflammation Full medical glossary
Special proteins in the blood that are produced in response to a specific antigen and play a key role in immunity and allergy. Full medical glossary
Inflammation of one or more joints of the body. Full medical glossary
Any condition caused by the body’s immune response against its own tissues. Full medical glossary
A fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. Full medical glossary
A disease of long duration generally involving slow changes. Full medical glossary
A group of hormones that are produced by the adrenal glands, which sit on top of the kidneys. Full medical glossary
The abbreviation for computed tomography, a scan that generates a series of cross-sectional x-ray images Full medical glossary
The raising of the body temperature above norma, which may be accompanied by symptoms such as shivering, headache and sweating. Full medical glossary
A viral infection affecting the respiratory system. Full medical glossary
An organ with the ability to make and secrete certain fluids. Full medical glossary
The oxygen carrying pigment that is present in red blood cells. Full medical glossary
Of unknown cause. Full medical glossary
The body’s response to injury. Full medical glossary
A large abdominal organ that has many important roles including the production of bile and clotting factors, detoxification, and the metabolism of proteins, carbohydrates and fats. Full medical glossary
An abbreviation for magnetic resonance imaging, a technique for imaging the body that uses electromagnetic waves and a strong magnetic field. Full medical glossary
Death of cells or tissue in the body due to disease, injury or impaired blood supply. Full medical glossary
Inflammation in more than four joints. Full medical glossary
An assessment of the likely progress of a condition. Full medical glossary
An organ situated on the left side of the abdomen that filters out worn-out red blood cells and other foreign bodies from the bloodstream. Full medical glossary
A tube placed inside a tubular structure in the body, to keep it patent, that is, open. Full medical glossary
Compounds with a common basic structure, which occur naturally in the body. The term may also refer to man-made drugs administered because they act like hormones. Full medical glossary
Affecting the whole body. Full medical glossary
trigeminal neuralgia Full medical glossary
An abbreviation for tumour necrosis factor, a protein that stimulates inflammation and causes cells to die. Full medical glossary
An abnormal swelling. Full medical glossary
A diagnostic method in which very high frequency sound waves are passed into the body and the reflective echoes analysed to build a picture of the internal organs – or of the foetus in the uterus. Full medical glossary
Relating to the sense of sight (vision). Full medical glossary
A type of electromagnetic radiation used to produce images of the body. Full medical glossary