Juvenile Idiopathic arthritis

Question 1

What is juvenile idiopathic arthritis?

Answer 1

• A peristent autoimmune inflammatory arthritis lasting > 6 wks in a pt younger than 16 years of age

Question 2

What is the epidemiology of juvenile idiopathic arthritis?

Answer 2

• _Joint involvment _
  
  • knee>hand/wrist> ankle > hip> C Spine
  • Female > male
• HLA Markers
  
  • DR4 assoc with polyarticular
  • DR8, DR5, DR2 assoc with pauciarticular
• RF seropositive in <15%

Question 3

what is the diagnostic criteria of juvenile idiopathic arthritis?

Answer 3

• A diagnosis of exclusion
• one must be present to make dx
  
  • rash
  • presence of RF
  • Iridocyclitis
  • C spine involvement
  • pericarditis
  • tenosynovitis
  • intermittent fever
  • morning stiffness

Question 4

What are the associated conditions of juvenile idiopathic arthritis?

Answer 4

• C spine involvment
  
  • kyphosis, facet ankylosis, atlantoaxial subluxation
• Occular involvment
  
  • iridocyclitis ( type of anterior uveitis)
  • can lead to rapid loss of vision if left untx
  • incrase risk with ANA titer
• Stills disease
  
  • acute onset JRA with multiple joint invovlement, fever, rash & spenomegaly
  • infection must be ruled out
  • male = female
  • usually present at 5-10 years

Question 5

What is the prognosis of juvenile idiopathic arthritis?

Answer 5

• 50% pt symptoms resolve without sequelae
• 25% slightly disabled
• 25% have crippling arthritis or blindness
  
  • best prognosis pauciarticular> polyarticular>systemic

Question 6

How is juvenile idiopathic arthritis classified?

Answer 6

• early onset= onset before teens
• Late onset= onset during teens/later
• Polyarticular (30%)
  
  • > 5 joints involved
  • small joint involved
  • symmetrical findings
  • hand/wrist commonly affected
    
    • wrist ulna deviation/flexion, MCP stiffness, extended, swollen, radially deviated digits
• Pauciarticular (50%)
  
  • < 5 joints affected
  • large joints involved
  • asymetrical findings
  • most common type
  • early onset assoc w iridiocyclitis 50% & chronic uveitis
  • PC- a limp that improves during the day
• Systemic (20%)
  
  • Systemic symptoms
  • includes Stills disease
  • poorest prognosis

Question 7

What are the signs and symptoms of juvenile idiopathic arthritis?

Answer 7

Symptoms

• Morning stiffness/joint pain
• visual changes
• fever

Signs

• Rash
• Iridocyclitis ( can lead to rapid loss of vision)

Question 8

What is seen on xrays of juvenile idiopathic arthritis?

Answer 8

• Often negative at presentation
• juxta-articular, late osteopenia & joint destruction can be seen if disease progressive
• Obtain flexion-extension neck xrays to rule out atlantoaxial instability

Question 9

What is seen on lab results with juvenile idiopathic arthritis?

Answer 9

• Rheumatoid factor
  
  • RF seropositive in <15%
    
    • assoc with higher incidence of chronic, active and progressive disease
    • more likely to progress into adult RA
  • RF seronegative more common
• ​Basic serology
  
  • values often normal and not diagnostic

Question 10

Describe the tx for juvenile idiopathic arthritis?

Answer 10

Non operative

• Immunomodulating drugs (DMARDS) and frequent ophthalmologic exams
  
  • first line
  • Disease modifying antirheumatic drugs
    
    • new class of medication that have a significant impact on outcomes
      
      • Etanercept= TNF inhibitor
      • Rituximab= Chimeric monoclonal antibody against CD20 on B cell surface
      • Azathioprine= purine synthesis inhibitor
  • ​​High dose aspirin/nsaids
    
    • ​salicylates used less frequently due to dmards
  • Intra-articular steriod injections
  • Frequent ophthalmic examinations
    
    • slit lamp every 4 months if ANA (+) annually if ANA (-ve)

Surgery

• Synovectomy
• epiphysiodesis
  
  • for LLD
  • affected leg typically longer
• Corrective osteotomies
  
  • for extremity deformity
  • deferred until skeletal mature
• Arthrodesis and arthoplasty
  
  • for severe disease