What is Juvenile Idiopathic Arthritis?
Juvenile idiopathic arthritis (JIA) is an umbrella term which is used to include a heterogenous group of conditions which begin in childhood and involve persistent inflammation in one or more joints.
The classification and terminology of chronic arthritis in childhood has been the source of much confusion and disagreement over the years, with the term juvenile chronic arthritis (JCA) being used in Europe and juvenile rheumatoid arthritis (JRA) in North America.
JIA occurs worldwide with an annual incidence of approximately 6-19 per 100 000 children and a prevalence rate of approximately 1 in 1000. These conditions are therefore a significant cause of childhood morbidity.
JIA is defined as arthritis beginning at less than 16 years, persisting for at least 6 weeks with no known cause.
Classification of JIA is based on the clinical characteristics of the individual's condition and the main ones are as follows:
Systematic
The least common but potentially fatal form of JIA which involves arthritis associated with marked systemic features.
Oligoarthritis
The most common form affecting between one and four joints during the first six months of the disease. Most commonly affected is the knee with the ankle being second.
Polyarthritis
(rheumatoid factor negative)
Children with arthritis affecting five or more joints during the first six months of the disease and are negative on testing for rheumatic involvement.
Polyarthritis
(rheumatoid factor positive)
Children with polyarthritis who are positive on testing for rheumatoid factor. Also known as juvenile rheumatoid arthritis, it is mainly seen in adolescent girls who develop a symmetrical polyarthritis usually affecting the small joints of the hands.
Bambach understands the problems associated with Juvenile Idiopathic Arthritis
- Joint swelling, pain and stiffness
- Children with inflamed joint will rapidly develop flexion deformities
- Persistent inflammation in a joint can lead to bony overgrowth
- Disturbance in growth
- Decreased bone mineral density (Osteopenia)
