Juvenile Rheumatic Arthritis / Juvenile Inflammatory Arthritis

Summary

• <16 y/o
•  Arthritis of 1 or more joints for >6 weeksduration
•  Peak age 1-3 y/o, then 9 y/o
• Type of JIA defined in 1st 6 months:
  • Polyarticular: 5 or more joints
  • Most common: Pauciarticular: 4 or fewer joints
  • Systemic: Prominent Fever, Rash, HSM…

Discussion

• may begin at any age
• commonly seen 1-4 y/o, girls > boys

Pauciarticular (most common)

• Approx half of all JIA cases
• 1-4 joints, usually large joints, usually knee; No fever
• serious complication: iridocyclitis, happens in many, esp girls with +ANA. It may present without clinical signs. ALWAYS do slit lamp exam
• chronic joint disease least likely in this form
• Type 1: Early Onset (Toddler females); "young female with chronic uveitis"
  • Joint: Minimal pain; asymmetric, typically affects knees (does not present in the hips), typically does not progress to joint destruction
  • Eye:50% get chronic iridocyclitis, can get bad uveitis, can progress to blindness, requires routine ophtho exams
  • Majority ANA (+)
  • Majority Females, <10y/o
• Type 2: Late Onset (Late childhood males); "8 year old male with symptoms of spondylo-arthropathy"
  • Joint: Tends to act like sponyloarthropathies with enthesitis & HLA-B27 (+) in 75%
  • Get SI and hip involvement
  • Later can develop one of the 4 main Spondyloarthropathies
  • Majority males, >10y/o
  • Best prognosis

Polyarticular JA (second most common)

• 5+ joints, both small and large. symmetric swelling of large joints, also, often hand; TMJ joint as well as the cervical spine are also frequently involved
• onset is insidious... low grade fever, lethargy
• often +ANA, only 5% +RF (Rheumatoid factor = anti-IG-G)
  • RF (+) (Adolescent females)
    • Typically the adolescent female
    • Later becomes adult Rheumatoid arthritis
    • Very destructive with the worst prognosis for permanent joint destruction
    • Can get rheumatoid nodules, Rash, Felty’s syndrome (Low WBC count with splenomegaly)
  • RF (-) (Late childhood)
    • Can getiridocyclitis/ chronic uveitis
    • Younger childhood
    • Less likely to get severe joint disease than RF(+)
• likely to persist, can cause deformities seen in adult Rheum arthritis

Systemic (least common)

• "Still's disease"; Associated with HLA-DRB1
• high spiking fever, returns to normal levels daily; Daily; 1-2x/day at the same time each day, with rapid return to normal and intermittent hypothermia (almost 100%)
• salmon-colored morbilliform/ macular/papular rash, anywhere over body (fleeting, evanescent during fever usually);  occasionally pruritic
• HSM, LAD
• Serositis(35%)
• at onset, arthritis seldom present and may not appear until several weeks or months after fever
• 1/3 get disabling chronic arthritis

DDX: other arthritis (infectious, ARF, reactive, CVD). JRA is different in that the joint manifestations persist.

DX: do x-rays only to exclude trauma. RF rarely positive. ANA nonspecific.

Tx: aspirin, may sub other NSAID ie motrin, tolmetin, naprosyn. Steroids, limited role, 2nd line if nsaids can't control fever. Gold salts during chronic phase. Last line: cytotoxic agents (MTX, cyclosporin A), biologics (Anti-TNF). PT/OT.

Followup:

Routine ophtho visits every few months for many years –depending on type of JIA and ANA status (generally every 3 months if ANA+ or <4y/o, every 6 months until 7y/o, and then annually if >7y/o without disease)

1. 3 y/o female with unilateral knee involvement and evidence of uveitis on ophtho eval
2. 13 y/o female with bilateral hand/ feet joint involvement and firm nodules over pressure points
3. 10 y/o male with hip involvement and achilles tendonitis
4. 5 y/o female with daily fever spikes, evanescent rash, and knee involvement

Answers

#1. Pauciarticular 1-Often ANA (+)
#2. Polyarticular –Expect RF (+)
#3. Pauciarticular 2 –Often HLA-B27 (+)
#4. Systemic JIA

CHLA Board Review 2005