Definition:

It can be defined as a persistent (>6 weeks) inflammatory disease that begins before the age of 16 and is characterized by idiopathic synovitis of peripheral joints associated with soft tissue swelling and effusion.

Causes of Juvenile rheumatoid arthritis:

1. Unknown
2. Environmental
3. Immunogenetic susceptibility to HLA
4. External triggering effect –

• Parvovirus B19
• Rubella virus
• EBV

Pathogenesis Juvenile rheumatoid arthritis:

i) Inflammatory swelling and congestion of the synovial membrane and underlying connective tissue
ii) The tissue is infiltrated with lymphocytes, plasma cells and macrophages
iii) Increased secretion of synovial fluid resulting effusion and hypertrophy of the synovial membrane
iv) Inflammatory granulation tissue spreads over and under the articular cartilage resulting progressive erosion and destruction
v) Fibrous or bony ankylosis and deformity due to adjacent muscle atrophy.

Criteria for diagnosis of Juvenile Rheumatoid arthritis (JRA):

1. Onset before 16 years of age
2. Arthritis (Swelling or effusion or presence of two or more of the following signs: limitation of range of motion, tenderness or pain on motion, increased heat) in one or more joints
3. Duration of disease is 6 weeks or more
4. Onset type:

• Oligoarthritis:<5 inflamed joints
• Polyarthritis: 5 or more inflamed joints
• Systemic arthritis with characteristic fever

5. Exclusion of other forms of Juvenile arthritis.

Investigations:

1. CBC with ESR: Hb -decreased, ESR- increased.
2. CRP – positive in Juvenile rheumatoid arthritis
3. Serological test: RF,ANA,HLA
4. X-ray of affected joints:

• Early changes: soft tissue swelling , osteoporosis, periosteitis
• Late change:narrowing of the joint space, bony destruction, fusion, deviation.

5. Analysis of synovial fluid
6. Synovial biopsy.

Treatment of Juvenile rheumatoid arthritis:

Treatment of Juvenile rheumatoid arthritis is given below-

1. Life style modification
2. Complete bed rest-if severely ill.
3. Physiotherapy
4. Occupational therapy
5. NSAID
6. Treatment of iridocyclitis – tropical use of steroids and dilating agents.
7. Surgery:

•  Synovectomy
• Total replacement arthroplasty.