Juvenile Idiopathic Arthritis Flashcards
What is juvenile idiopathic arthritis?
A group of systemic inflammatory disorders affecting children under 16 yrs
Which factors contribute to the aetiology JIA?
- Genetic
- Environmental
- Immunologic
What are the criteria for diagnosing JIA?
- Age of onset < 16 yrs
- Duration > 6 weeks
- Joint swelling OR
- Two of: painful/limited joint movements, tenderness and warmth
What are the main subtypes of JIA?
- Pauciarticular (most common): 4 or less joints
- Polyarticular: 5 or more joints
- Systemic onset
Why is knowing the subtype of the JIA of benefit?
- Natural history
- Complications
- Prognosis
- Strategy of treatment
Which population groups are most likely to have Type 1 Pauciarticular JIA?
- Age: before 5 yrs (peak: 1-3)
- Girls > boys
What is the presentation of Type 1 Pauciarticular JIA?
- Limp rather than pain
- Mainly LL
- Knee > ankle > hand or elbow (hip is rare)
- Positive ANA in 40-75%
- Chronic uveitis in 20%
What is the presentation of Type 2 Pauciarticular JIA?
- Age > 8/9
- Boys > girls
- Limp due to LL affection
- Mainly LL joints: knees and ankles
- Hip can be affected with rapid damage (may need THR early in life)
What are the features of juvenile ankylosing spondylitis?
- Features of type 2 pauciarticular JIA
- HLA-B27
- Back involvement
- Chronic iridocyclitis in 10-20%
What are the features of type 3 pauciarticular JIA?
- Any age
- Girls > boys
- Asymmetrical UL and LL arthritis
- Dactylitis
- Can be very destructive
- FH of psoriasis
- +/- nail pitting
- Chronic iridocyclitis in 10-20%
What is the presentation of RF negative polyarticular JIA?
- Any age (often early)
- Girls > boys
- Constitutional manifestations (low grade fever, malaise)
- Hepato-splenomegaly
- Mild anaemia
- Growth abnormalities
- Symmetric large and small joints affection: knees, wrists, ankles, MCPs, PIPs and neck
What is the presentation of RF positive polyarticular JIA?
- Age: late childhood
- Girls > boys
- Constitutional manifestations (low grade fever, malaise and weight loss)
- Anaemia
- Nodules
What are the potential complications of RF positive polyarticular JIA?
- Sjogren’s syndrome
- Felty or vasculitis
- AR
- Pulmonary fibrosis
- AAS
- CTS
What is the presentation of systemic onset JIA?
- Age: throughout childhood (4-6yrs)
- Girls > boys
- Fever of 39.5 C for at least 2 weeks in the afternoon or evening
- Rash on trunk and thighs
- Generalised lymphadenopathy
- Hepatosplenomegaly
- Abdominal pain +/- transaminases
- Polyserotitis
- Pericarditis in 36%
- Rarely pleural effusion or pulmonary fibrosis
- Arthritis: wrists, knees, ankles, cervical spine, hips and TMJ
What are the potential complications of uveitis in JIA?
- Posterior synechiae
- Cataracts
- Band keratopathy
