Different types of Juvenile Idiopathic Arthritis

Oligoarthritis

The most common type – affects about two thirds of young people with arthritis. It’s often mild. Oligoarticular arthritis means arthritis affecting only a few (four or less) joints.
Most commonly affects one or both knees. Most likely type to cause eye inflammation (chronic anterior uveitis) – you’ll need regular eye checks.
  • Most likely type to go away leaving little or no joint damage.
  • The disease may be associated with chronic inflammation in the eyes called chronic anterior uveitis (especially if blood tests show the presence of an antibody called antinuclear antibody or ANA).
  • The eye disease usually does not cause obvious redness, swelling or pain, but if left untreated may cause visual impairment. Regular examination of the eyes using a slit lamp is therefore essential for this group of children.
If you develop problems with five or more joints after six months, this is called extended Oligoarthritis. This can cause joint damage. Your doctor may suggest early treatment with drugs like methotrexate to keep the damage to a minimum.

Polyarthritis

  • The second most common type of JIA.
  • Polyarticular JIA means arthritis affecting five or more joints.
  • It may come on suddenly or can steadily involve more joints over a period of months.
  • Painful swelling in fingers, toes, wrists, ankles, hips, knees, the neck and jaw.
  • You may feel unwell and tired and occasionally develop a slight fever.
  • Symptoms may continue into adult life, but it can go into remission, where all the symptoms disappear.
  • A blood test will show whether a marker called rheumatoid factor is present in your blood.

Enthesitis-related JIA

  • Affects the places where the tendons attach to the bone (entheses), causing inflammation.
  • Often affects the joints of the leg and spine.
  • Associated with a red painful eye condition (acute uveitis).
  • You may develop stiffness in your neck and lower back in your teens.
  • There may be a family history of ankylosing spondylitis or inflammatory bowel disease because of a particular genetic marker called HLA-B27.

Psoriatic Arthritis

  • Psoriasis is a skin rash. A combination of joint pain and the rash is known as psoriatic arthritis.
  • Usually affects fingers and toes but may affect other joints too.
    Joints may be affected before the psoriasis appears – your doctor may look closely at fingernails and toenails for early signs.
  • Uveitis is fairly common but it’s the painless type that doesn’t look red.
  • It’s difficult to predict, but between 30-40% have ongoing disease into adulthood.
  • Your doctor may ask if anyone else in your family has the condition.

Systemic-onset JIA

  • Systemic-onset JIA is rare. It can cause joint pain and swelling, as well as inflammation all over the body.
  • Enlarged glands in your neck, under your arms and around your groin.
  • Your doctor may find your spleen and liver are enlarged, and, very occasionally, the covering of your heart is inflamed (pericarditis).
  • In the first few weeks there may be no sign of swollen joints, and the diagnosis may be uncertain.
  • It can be difficult to predict how it’ll affect you but usually the fever and rash will settle, although the arthritis may continue for several years before settling.
  • Lots of tests may be needed to confirm the diagnosis and this can be a worrying time.