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Flashcards in Juvenile Idiopathic Arthritis Deck (32)
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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


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
-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
-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)
-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)
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?

-Pulmonary fibrosis


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
-Tamponade and myocarditis
-Generalised non-tender lymphadenopathy
-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


What is the 1st line therapy for JIA?

-Simple painkillers


What is the 2nd line therapy for JIA?

If no response to NSAIDs/ joint (steroid) injections.
(Rarely needed in oligoarticular JIA)
-Methotrexate (pharmocokinetics is age related).
-Anti-TNF Rx. (all 3): In methotrexate failure.
-IL-1 R-antagonist (Anakinra) in refractory systemic arthritis.
-IL-6 antagonist (Tocilizumab) for refractory systemic disease.


Why is there limited indications for systemic steroids?

Due to their serious side effects


What are systemic steroids used in?

-Systemic JIA (control pain and fever)
-Serious disease complications with any subtype e.g. periocordial effusion, tamponade, vasculitis, severe auto-immune anemia, severe aye disease
-As a bridge between DMARDs
-Children undergoing surgery


What are the risks of systemic steroid use?

-Growth abnormalities


When are local steroids used?

-Intra-articular mainly in Oligo-articular JIA
-Eye disease (ANA +ve oligo-articular disease