JUVENILE RHEUMATOID ARTHRITIS (JRA)

This condition is an arthritis beginning at or before the age of 16 years and tends to affect large and small joints and may interfere with growth and development.

Stiffness is usually worse in the morning and the child may be reluctant to use the affected limb(s).

Classification

Juvenile rheumatoid arthritis is classified into three grouping:

  • Systemic (Still’s disease)
  • Pauciarticular types I and II
  • Polyarticular varieties.

Presentation of juvenile rheumatoid arthritis, by type

Type Systemic disease Pauciarticular (JRA) Polyarticular
(JRA)
Frequency of occurrence
as a percentage
20% 40% 40%
Rheumatoid factor test -ve -ve +/-+ve/-ve
Antinuclear factor test -ve 75% +ve
HLA B27 antigen test +/-+ve/-ve -ve
Presentation High fever, rash, splenomegaly generalized lymphadenopathy serositis, striking leucocytosis and thrombocytosis Type I: mainly male, Type II: mainly female arthritis As for adult rheumatoid arthritis

Management

  • Treat as outpatient:
    • Physiotherapy
    • Acetylsalicylic acid children 75–100mg/kg QDS
    • Regular eye check up to detect eye complications and care
  • Admit for:
    • Acute exacerbation
    • Bed rest (may need to splint the affected joint)
    • Intensive physiotherapy
    • Systemic complications
  • Refer if:
    • Deformities are present (seek surgical opinion)
    • Disease does not respond to NSAIDs
    • There is systemic organ involvement

Prognosis

  • Overall prognosis for juvenile rheumatoid arthritis is better than that for adult rheumatoid arthritis.
  • Complete remission occurs in 50–75% of patients.
  • Those with polyarticular form of the disease and are RhF positive have a less favourable prognosis.