This is the most common type of JIA and affects four or fewer joints. Symptoms are swollen, painful joints, particularly the knees and/or ankles. Eye inflammation is common and specialist eye checks are needed. Many children with oligoarthritis improve after some time, but if a few joints remain swollen, the disease is termed persistent oligoarthritis. If the disease worsens, and more joints become involved, it is called extended oligoarthritis. It tends to affect girls more commonly than boys.
This is when 5 or more joints are affected in the first 6 months of the illness. As well as pain and stiffness in joints other symptoms include tiredness and eye inflammation.
Systemic onset JIA
This is a rare type of arthritis in which joint pain is accompanied by general illness. It begins with symptoms such as fever, rashes, lethargy (tiredness) and swelling of the lymph glands in the neck, underarm and groin. Early signs are often mistaken for an infection. Rarely, the lining of the heart (pericarditis) or lungs (pleuritis) may become inflamed.
Enthesitis related arthritis
This occurs due to inflammation of tendons or ligaments where they attach to bone. The condition may also cause painful areas in the soles of the feet or other areas around the knees or hips. Stiffness and pain in the spine are uncommon in childhood, but can persist into adulthood (known as ankylosing spondylitis in adults-see entry).
Psoriatic Arthritis (see entry Psoriatic Arthritis in Children).