Juvenile Idiopathic Arthritis Flashcards
What is juvenile idiopathic arthritis?
- Group of systemic inflammatory disorders affecting children below age of 16 years.
- The most commonly diagnosed Rheumatic disease in children.
What is juvenile idiopathic arthritis an important cause of?
Disability and blindness
What is the aetiology and pathogenesis of JIA?
- JIA is an auto-immune disease.
- Etiopathogenesis is multi-factorial and different from that of adult RA.
- Strong subset-specific genetic markers may affect immune response
What is the criteria for diagnosis of JIA?
Age of onset
-<16 years
Duration of disease
->6 weeks
Presence of arthritis (Joint swelling or 2 of the following:)
- Painful or limited joint movement
- Tenderness
- Warmth
When can subtypes of JIA be identified?
After 6 months
What are the 3 major subtypes of JIA?
- Pauciarticular 55%
- Polyarticular 25%
- Systemic onset 20%
What clinical subtypes of JIA have recently been identified?
- Enthesopathy related arthritis
- Juvenile psoriatic arthritis: oligo or spondylo with psoriasis or potential psoriasis
- Others: unclassified under above criteria
How is pauciarticular JIA divided?
- Type I 25%
- Type II 15%
- Type III 15%
What is the classical presentation of type I pauciarticular JIA?
- Preschool girls
- Limp rather than pain
- Mainly LL joints
- Knee>ankle>hand or elbow (hip very rare)
- Chronic uveitis
- Irregular iris due to posterior synechiae
- +ve ANA
- Can be asymptomatic
How is pauciarticular JIA defined?
4 or less joints
What is the classical presentation of type II pauciarticular JIA?
- Primary aged boys (8-9)
- Limp due to LL affection
- Mainly LL joints: knee and ankle
- Hips may be affected early with rapid damage requiring THR
- Enthesitis
- Can develop AS or spondyloarthritis
Which individuals with type II pauciarticular JIA are categoreised as juvenile ankylosing spondylitis?
Those with HLA-B27 + back involvement
What is the classical presentation of type III pauciarticular JIA?
- Girls during childhood
- Asymmetric UL and LL arthritis
- Dactylitis
- Chronic iridocyclitis
- FH of psoriasis
What can happen to those with extended oligoarthritis?
30% of these presenting with pauciarticular JIA can go on to more severe polyarticular course.
How is polyarticular JIA defined?
5 or more joints
What is the classical presentation of RF- polyarticular JIA?
- Girls of any age (often early)
- Constitutional manifestations (low grade fever, malaise)
- Hepato-splenomegaly
- Mild anemia
- Growth abnormalities
- Symmetric large and small joints affection: knees, wrists, ankles, MCPs, PIPs, neck
- Iridocyclitis rare
What is the classical presentation of RF+ polyarticular JIA?
-Girls in later childhood (including teens)
-Constitutional manifestations (low grade fever, malaise, weight loss)
-Anaemia
-Nodules
Iridocyclitis is rare
-Similar to adult RA
What can be seen on x-ray of RF+ polyarticular JIA?
Erosions which occur early
What can complicate RF+ polyarticular JIA?
- Sjorgen’s
- Felty
- Vasculitis
- AR
- Pulmonary fibrosis
- AAS
- CTS
How is systemic onset JIA defined?
Extra-articular features which start early and disappear after 2-5 years
What is another name for systemic onset JIA ?
Still’s disease
What is the classical presentation of Still’s disease?
- F:M 1.5:1
- Occurs throughout childhood (4-6 years)
- Joints affected include wrists, knees, ankles, cervical spine, hips and TMJ
- Evanescent salmon red eruption on trunk and thighs accompanised by fever. Exhibits Koebner’s phenomenon
What extra-articular features can be present in Still’s disease?
- Pleural effusion
- Pulmonary fibrosis
- Polyserositis
- Pericarditis
- Tamponade and myocarditis
- Generalised non-tender lymphadenopathy
- Hepatosplenomegaly
- Abdominal pain +- transaminases
Describe the associated fever of Still’s disease.
- Rise to 39.5 C 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 +/- chills but looks normal when fever goes away
