Juvenile Idiopathic Arthritis

 

Systemic Onset

á       Epidemiology: M=F, 1-6yo

á       Signs and symptoms:

o   High spiking fevers daily or twice daily

o   Evanescent salmon-colored rash

o   Lymphadenopathy, hepatosplenomegaly, pericarditis

á       Labs: RF(-), ANA(-), increased ferritin, leukocytosis, anemia, increased ESR

á       If persists: osteoporosis, short stature, brachydactyly, micrognathia

á       Differential: infection (bacterial, viral), malignancy, inflammatory bowel disease, acute rheumatic fever, systemic vasculitides (polyarteritis nodosa), collagen vascular disease (SLE)

á       Complications: Pericardial tamponade, systemic vasculitis, macrophage activation syndrome (persistent high fever, pancytopenia, active phagocytosis on bone marrow biopsy)

 

Pauciarticular

á       Epidemiology: F>M, 2-3yo, rare <10yo

o   Persistent – affects no more than 4 joints after 6mo

o   Extended – affects more than 4 joints after 6mo ˆ erosive arthritis, treatment: immunosuppressant

á       Signs and symptoms:

o   ²4 joints especially knee and ankle

o   Uveitis

á       Labs: ANA(+)

á       If persists: leg length discrepancy, eye problems (corneal clouding, cataracts, glaucoma, visual loss)

á       Differential: infection (get joint aspiration to rule out), Lyme, postviral, trauma, malignancy, mechanical

 

Polyarticular

á       RF(+)

o   Epidemiology: F>M, ³8yo, (+)HLA-DR4

o   Signs and symptoms: symmetric, small joints

o   Complications: severe erosive arthritis, rheumatoid nodules, worse prognosis than RF(-)

á       RF(-)

o   Epidemiology: F>M, younger (2-5yo)

o   Signs and symptoms: asymmetric, fewer joints, ANA(+)

á       Other signs and symptoms: fatigue, malnutrition, delayed growth, anemia, osteopenia

á       Differential: Lyme, gonorrhea, viral, SLE, scleroderma, dermatomyositis, spondylarthropathies, malignancy

 

Enthesitis-related

á       Epidemiology: M>F

á       Signs and symptoms:

o   Inflammation of enthesis (tendon attaches to bone) ˆ heel pain, arthritis

o   Sacroiliac joint tenderness, inflammatory spinal pain, HLA-B27, family history, uveitis, pauciarticular or polyarthritis in >8yo M

á       If persists: spondyloarthropathies (ankylosing spondylitis, reactive arthritis, IBD-associated arthritis)

 

Psoriatic

á       Signs and symptoms: arthritis, psoriasis, dactylitis, nail pitting (onycholysis), family history of psoriasis

 

Treatment

á       1st line: NSAIDs (SE: abdominal pain, anorexia)

á       Disease-modifying anti-rheumatic drugs (DMARDs): methotrexate plus 1mg folic acid (SE: GI – oral ulcers, decreased appetite, abdominal pain), sulfasalzine, steroids (only short-term for severe manifestations)

á       Other – Etanerecpt (TNF-R antagonist), joint replacement surgery, autologous stem cell transplant (last resort)

á       PT/OT, splints, screen for uveitis

 

Reference: Goldmuntz EA and White PH. Juvenile Idiopathic Arthritis: A Review for the Pediatrician. Pediatrics in Review 2006; 27(4): e24-e32.