Juvenile idiopathic arthritis (JIA) is a collective term used to describe a group of arthritides that affect children and young individuals under the age of 16, where the etiology is unknown

Aetiology

• The exact aetiology of JIA remains unknown
• However, it is thought to involve a combination of genetic susceptibility and environmental factors leading to immune dysregulation and inflammation in joints and other tissues

Clinical features

• Initial presentation of juvenile idiopathic arthritis usually involves systemic signs, followed by joint symptoms
• Systemic signs may include:
  • Fevers
  • Generalised malaise
  • Salmon pink rash
• Joint involvement can affect a single or multiple joints, leading to:
  • Joint pain
  • Joint swelling
  • Morning stiffness
  • Limited range of motion

Investigations

• The diagnosis of JIA is primarily clinical, made once other potential causes have been ruled out
• Investigations that can aid in the diagnosis and exclusion of other conditions include:
  • Blood tests: FBC, ESR, CRP, Antinuclear antibodies (ANA), Rheumatoid factor (RF)
  • Imaging: ultrasound or MRI of affected joints may reveal synovial hypertrophy, effusion or bone erosion
  • Joint aspiration: to rule out infection or malignancy

Management

• Management of JIA is comprehensive and often requires input from a multi-disciplinary team including paediatricians, physiotherapists, orthopaedic specialists, occupational therapists, and ophthalmologists
• Emotional and psychological support is crucial as JIA can be extremely debilitating and patients may require assistance coping with the requirement for walking aids early in life
• Medical management strategies include:
  • NSAIDs: primarily for symptom control
  • Steroids: can be administered either intra-articular or orally for controlling inflammation
  • Steroid-sparing agents: methotrexate or biological agents such as TNF-alpha inhibitors may be used to minimize long-term steroid use