Ch. 155 Juvenile Idiopathic Arthritis Flashcards
MC rheumatic disease in children
JIA (JRA accdg to ACR)
MC subtype of JIA in order
1) Oligoarthritis 40-50% 2) Poly- 3) Systemic
Gender predominance in sJIA
None
Gender predominance in oligo- and polyarticular JIA
F>M
Peak of onset of oligoarthritis
2-4 y/o
Peak of onset of polyarthritis
Bimodal, 2-4 y/o and 10-14 y/o
Peak of onset of sJIA
1-5 y/o
Non-genetic triggers for JIA
1) Viral and bacterial infections 2) Enhanced immune responses to bacterial or mycobacterial heat shock proteins 3) Abnormal reproductive hormone levels 4) Joint trauma
Components of the immune system affected in JIA
Both humoral and cell-mediated immunity
Cell type that plays a central role in the pathogenesis of JIA
T lymphocytes
Inflammatory synovitis in JIA is characterized pathologically by
Villous hypertrophy and hyperplasia with hyperemia and edema of synovial tissue
Advanced and uncontrolled JIA leads to
1) Pannus formation 2) Progressive erosion of articular cartilage and contiguous bone
Must be present to make a diagnosis of any JIA subtype
Arthritis
Criteria for classification of JRA
1) Age of onset <16 yrs 2) Arthritis in >1 joint 3) Duration ≥6 weeks Exclusion of other forms of juvenile arthritis
Arthritis of JRA is defined as
Swelling or effusion or presence of 2 or more of the ff: 1) Limitation of ROM, tenderness or pain on motion 3) Increased heat
Polyarthritis is defined as
≥5 inflamed joints
Oligoarthritis is defined as
≤4 inflamed joints
Arthritis + rash + characteristic quotidian fever
Systemic JIA
ILAE Classification of JIA: Systemic onset JIA
1) ≥1 joint with or preceded by fever of at least 2 weeks, daily, quotidian for at least 3 days 2) Evanescent erythematous rash 3) Generalized LN enlargement 4) Hepatomegaly and/or splenomegaly 5) Serositis
ILAE Classification of JIA: Oligoarticular JIA
1) 1-4 joints during first 6 months 2) PERSISTENT: 1-4 throughout entire disease course 3) EXTENDED: >4 after 1st 6 months
ILAE Classification of JIA: Polyarthritis RF negative
≥5 joints during 1st 6 months, RF negative
ILAE Classification of JIA: Polyarthritis RF positive
≥5 joints during 1st 6 months, RF positive in ≥2 tests at least 3 months apart during 1st 6 months of disease
Spondyloarthropathies: Psoriatic arthritis, criteria
Arthritis + psoriasis OR arthritis + at least 2 of the ff: 1) Dactylitis 2) Nail pitting and onycholysis 3) Psoriasis in a 1st degree relative
Spondyloarthropathies: Enthesitis-related arthritis, criteria
Arthritis + enthesitis or arthritis or enthesitis with at least 2 of the ff: 1) Presence or history of SI joint tenderness and/or inflammatory lumbosacral pain 2) HLA-B27 positive 3) Onset >6 y/o in a male 4) Acute symptomatic anterior uveitis 5) History of ankylosing spondylitis, enthesitis-related arthritis, sacroiliitis, with IBD, Reiter syndrome, or acute anterior uveitis in a 1st degree relative
HLA-B27 positive
Enthesitis-related arthritis
T/F In JIA, involvement of the hip is almost never a presenting sign
T, suggests a spondyloarthropathy or a nonrheumatologic cause
Confers increased risk for asymptomatic anterior uveitis
(+) ANA
PE finding that reflects chronic temporomandibbular joint disease
Micrognathia
Rash of systemic JIA
Evanescent, salmon-colored, linear or circular, most common over trunk and proximal extremities
Rare but potentially fatal complication of SoJIA
MAS
Clinical manifestations of SoJIA
Acute profound anemia, thrombocytopenia, leukopenia, high spiking fevers, lymphadenopathy, hepatosplenomegaly
Preliminary diagnostic guidelines for MAS complicating JIA: Lab criteria
1) Decreased platelet count 2) Elevated AST 3) Decreased WBC 4) Hypofibrinogenemia
Preliminary diagnostic guidelines for MAS complicating JIA: Clinical criteria
1) CNS dysfunction 2) Hemorrhages 3) Hepatosplenomegaly
Preliminary diagnostic guidelines for MAS complicating JIA: Histopath criterion
Macrophage hemophagocytosis in the BM aspirate
Preliminary diagnostic guidelines for MAS complicating JIA: Diagnostic rule
2 or more lab criteria OR ≥2 clinical and/or lab criteria
T/F JIA is a clinical diagnosis of exclusion
T
Associated with increased risk of chronic uveitis in JIA
(+) ANA
Treatment for JIA
NSAIDs, MTX, TNF-α antagonist
JIA Type, Types of Joints: Medium to large
Oligo
JIA Type, Types of Joints: Small to medium
Poly, systemic
JIA Type, Eye disease (uveitis): +++
Oligo
JIA Type, Eye disease (uveitis): ++
Poly
JIA Type, Eye disease (uveitis): +
Systemic
JIA Type: ANA ++
Oligo
JIA Type: ANA +
Poly
JIA Type: ANA -
Systemic
JIA Type: RF (+)
Poly
JIA Type, Outcomes: Excellent, >90% complete remission
Oligo
JIA Type, Outcomes: Good, >50% complete remission
Poly
JIA Type, Outcomes: Variable, depends on extent of arthritis
Systemic
