Previously called juvenile rheumatoid arthritis and juvenile chronic arthritis, this is a set of related conditions of unknown cause affecting children. Characteristically, the synovial membrane of a joint or joints becomes inflamed and swollen for at least six weeks (and often for much longer – even years). About 1 in 10,000 children develop it each year, many of whom have certain HLA genetic markers, thought to be important in determining who gets the illness. Inflammatory CYTOKINES play an important part.
There are various types. The oligoarthritic type involves 1–4 joints (usually knee or ankle) which become hot, swollen and painful. One complication is an inflammation of the eyes – UVEITIS. The condition often ‘burns out’, but may reappear at any time, even years later.
The polyarthritic type is more like RHEUMATOID ARTHRITIS in adults, and the child may have persistent symptoms leading to major joint deformity and crippling.
The systemic type, previously called Still's disease, presents with a high fever and rash, enlarged liver, spleen and lymph nodes, and arthritis – although the latter may be mild. In some children the illness becomes recurrent; in others it dies down only to return as polyarthritis.
These include uveitis, which can lead to loss of vision; a failure to thrive; osteoporosis (see under BONE, DISORDERS OF); joint deformity; and psychosocial difficulties.
This includes ANTIPYRETICS and ANALGESICS, including NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS), intra-articular steroid injections, anti-tumour necrosis factor drugs, and steroids.
Physiotherapy is vital, and children may need to wear splints or other orthotic devices to alleviate deformity and pain. Orthopaedic operative procedures may be necessary.