Juvenile Idiopathic Arthritis Flashcards
What is the definition of Juvenile idiopathic arthritis?
Group of systemic inflammatory disorders affecting children below age of 16 years
What is the aetiology and pathogenesis of JIA?
how does this compare to RA?
JIA is an auto-immune disease
Aetiopathogenesis is multifactoral and different from that of adult RA
Genetic
Environmental
Immunologic
(We dont really know)
What is the criteria for diagnosis of JIA?
Age of onset 6 weeks
Joint swelling or 2 of:
- Painful or limited joint motion
- Tenderness
- Warmth
What are the 3 major subtypes of JIA?
Pauciarticular (55%)
Polyarticular (25%)
Systemic onset (20%)
Appart from the 3 major subtypes of JIA what other clinical subtypes are there?
Enthesopathy related arthritis
Juvenile psoriatic arthritis:
-oligo or spondylo with psoriasis or potential psoriasis
Others:
-Unclassified under above criteria
How many joints are effected in Pauciarticular JIA?
4 or less joints
How many types of Pauciarticular JIA are there?
3 types:
- Type 1 (25%)
- Type II (15%)
- Type III (15%)
What joints are usually affected in Pauciarticular JIA type 1?
Mainly lower limb
Knee > ankle > hand or elbow (hip very rare
What is the presentation of Pauciarticular JIA type I?
who is it most common in?
Limp rather than pain
-Young children dont really report pain
Preschool aged girl under 5 (peak 1-3)
M:F = 1:8
Why do you check ANA in pauciarticular JIA type I?
Positive ANA in 40-75%
Chronic uveitis in 20% of cases (95% if female
What is the presentation of Pauciarticular JIA type II?
who is it most common in?
Constitutional rare
Limp due to lower limb being more effected
Age: after 8-9
M:F = 7:1
What joints are most effected in pauciarticular JIA type II?
Mainly lower limb: knee, ankle
Hip can be affected early with rapid damage requiring total hip replacement early in life + enthesitis + many have sacroiliac joints and may evolve AS or spondyloarthritis
When is someone categorised as having Juvenile Ankylosing Spondylitis?
Those with HLA-B27 and back involvement in pauciarticular JIA type II
What is the presentation of pauciarticular JIA type III?
who does it commonly present in?
- Constitutional rare
- Asymmetric upper and lower limb arthritis
- Dactylitis
Any age during childhood
M:F = 1:4
What family history do patients with pauciarticular JIA commonly have?
What does this mean for them?
FH of psoriasis in 40%
+/- nail pitting
These patients may develop psoriases later in life
What eye disease can occur in each type of pauciarticular JIA?
Type I:
- Chronic uveitis in 20% of cases
- If female under 2 years then 95% of cases
Type II:
-Acute iridocyclitis in 10-20%
Type III:
-Chronic iridocyclitis in 10-20%
How many joints are affected in polyarticular JIA?
5 or more joints
How does RF -ve Polyarticular JIA normally present?
who does it present in? What joints are effected?
Can presentt in any age, often early
M:F = 1:9
- Constitutional manifestations (low grade fever, malaise)
- Hepato-splenomegaly
- Growth abnormalities
Symmetric large and small joints:
-Knees, wrists, ankles, MCPs, PIPs, neck
What are the two types of Polyarticular JIA?
RF +ve
RF -ve
How does RF +ve Polyarticular JIA normally present?
who does it present in? etc
Age: late childhood (teens, 12-16 years
M:F 1:7
- Constitutional manifestations (low grade fever, malaise, weight loss)
- Anaemia
- Nodules
What can RF +ve polyarticular JIA be complicated by?
What is it similar to?
Complicated by:
- Sjogren’s
- Felty or vasculitis
- AR
- Pulmonary fibrosis
- AAS, CTS
Similar to adult RA but in a child
Erosions in x-ray occur early
How common is iridocyclitis in both types of polyarteritis JIA?
Rare in both RF +ve and -ve
What is systemic onset JIA also called?
Still’s disease
after George Frederic Still
What is the epidaemiology of Systemic onset JIA?
- Age: throughout childhood (4-6 years)
- M:F = 1:1.5
Rare
Extra-articular features define systemic onset JIA.
What are these features?
think of the organs effected
- Pleural effusion
- Pulmonary fibrosis
- Polyserositis
- Pericarditis in 36%
- Tamponade and myocarditis
Fever
Hepatospenomegaly 50-75%
Abdominal pain
+/- transaminases
Generalised lymphadenopathy (50-75%) -Non tender
Evanescent salmon red eruption (90%)
- trunk and thighs
- Positive Koebner’s phenomenon
Explain fever in children with systemic onset JIA
How high is it?
What is its pattern?
- Fever of 39.5 degrees daily for at least 2 weeks
- Late in afternoon or evening and returns to normal or subnormal in the morning
- Child appears toxic with fever +/- chilld but looks normal when fever goes away
What joints are effected in systemic onset JIA?
When do joint problems occur?
Within 3-12 months of onset of fever
Wrists, knees, ankles, cervical spine, hips and TMJ
What tests can you carry out in juvenile idiopathic arthritis?
No diagnostic tests
ASO: often elevated with no evidence of recent strep infection
RF: 15-20% of children with late onset polyarticular JIA
ESR: Often elevated,
- Very high in systemic JIA,
- Does not correspond with disease activity
ANA: 40-60% of pauciarticular JIA
What is the 1st line therapy in JIA?
Simple pain killers
NSAIDs
-Children can take these for years without any GI upset. (much more tough than adults)
What is second line therapy in JIA?
Joint (steroid) injections
Methotrexate (can give much more to children than adults)
Anti TNF (if methotrexate fails)
IL-1 antagonist (Anakinra)
-Refractory systemic arthritis
IL-6 antagonist (Tocilizumab)
-Refractory systemic disease
When are systemic steroirds used?
Systemic JIA (control pain and fever)
Serious disease complications with any subtype e.g. periocordial effusion, tamponade, vasculitis, severe autoimmune anaemia, severe eye disease)
As a bridge between DMARDs
Children undergoing surgery
Why are systemic steroids only used in special indications?
Serious side effects:
- Risk of osteoporosis
- Infections
- Growth abnormalities
When are local steroids used in JIA?
Intra-articular mainly in oligo-articular JIA
Eye disease (ANA +ve oligo-articular disease)
What surgical treatment can be considered in Juvenile Idiopatic Arthritis?
Synovectomy
Reconstructive/ joint replacement surgery
