What is childhood arthritis?
Introduction
Juvenile Idiopathic Arthritis (JIA) is an inflammation of one or more joints, that lasts for more than six weeks, and occurs in children under sixteen. JIA is an umbrella term that covers different forms of arthritis in children, and was formerly known as Juvenile Idiopathic Arthritis. In America, it is still sometimes known as Juvenile Rheumatoid Arthritis, and there is some overlap and confusion about names and classification of subgroups.
In most regions, about one in every thousand children develop some form of ongoing arthritis which is a similar incidence to cerebral palsy or cystic fibrosis. There are infective forms that occur in small populations but which are now very rare in Europe and North America.
What causes arthritis?
We still do not know what causes arthritis in childhood. There would appear to be a number of factors that seem significant, and these are being actively studied. It is extremely rare for brothers or sisters to develop arthritis, but it can happen.
There would appear to be a small inherited factor in spondylo-arthritis and psoriatic groups. There is no research evidence that the weather effects people with arthritis. It is known that stress, that causes us to become more tense, can influence symptoms and the experience of pain.
Different forms of juvenile arthritis
In 1999 leading international clinicians agreed to a new classification. This was :
| Old Name | New Name |
|
Systemic onset Juvenile Idiopathic Arthritis (JCA) [rash, spiking fever and joint inflammation] |
Systemic onset Juvenile idiopathic arthritis (JIA) |
|
Pauci-articular JCA [four or less joints in first six months] | Oligoarticular JIA |
|
Extended pauci-articular JCA [more than four joints after six months] | Extended oligo-articular JIA |
|
Seronegative polyarticular JCA [as above, with no rheumatoid factor] | Rheumatoid factor negative polyarticular JIA |
|
Juvenile rheumatoid arthritis [more than five joints, with rheumatoid factor] | Rheumatoid factor positive polyarticular JIA |
| Psoriatic JCA | Psoriatic JIA |
| Spondyloarthropathy JCA | Enthesitis related JIA |
Children with other conditions, (for example Ehlers-Danlos Syndrome, Crohn's Disease) can experience daily consequences of disease that are very similar to children with the above conditions.
In this book, the term juvenile arthritis is used because the majority of experiences are shared by the children and families irrespective of the specific diagnosis.
