Juevenile Idiopathic Arthritis Flashcards
Juvenile idiopathic arthritis
- JIA is an auto-immune disease.
- Etiopathogenesis is multi-factorial and different from that of adult RA
- prevalence 1/1000 under 16 years
JIA characterised by:
- Age of onset <16 years
- Duration of disease >6 weeks
- Joint swelling or 2 of the following:
- Painful or limited joint motion
- Tenderness
- Warmth
After 6 months, 3 major subtypes can be identified:
- pauciarticular
- polyarthritis
- systemic onset
Pauciarticular JIA
- 4 or less joints
- 55% - most common
- Type I, Type II, Type III
Pauciarticular JIA Type I
- 25%
- age <5
- girls>boys
Pauciarticular JIA Type I presentation
- limp rather than pain
- no constitutional manifestations
- mainly LL joints
- knee > ankle > hand or elbow
- +ve ANA in 40-50%
- chronic uveitis in 20% of cases
Pauciarticular JIA Type II
- 15%
- age >8
- boys>girls
Pauciarticular JIA Type II presentation
- constitutional rare
- limp due to LL affection
- mainly LL joints: knee, ankle
- hip can be affected early with rapid damage requiring THR early in life
- those with HLA-B27 and back involvement will be categorised as Juvenile Ankylosing spondylitis
Pauciarticular JIA Type III
- 15%
- age: any age during childhood
- girls>boys
Pauciarticular JIA Type III presentation
- constitutional rare
- asymmetric upper limb and lower limb arthritis
- dactylitis
Pauciarticular JIA Type III prognosis
- arthritis can be very destructive
- +/- nail pitting
- family history of psoriasis in 40%
- these patients may develop psoriasis later in life
Polyarticular JIA
- 5 or more joints
- 25% second most common
- RF -ve
- RF +ve
Polyarthritic JIA RF -ve
- 15% of JIA
- age: any age
- girls>boys
Polyarthritic JIA RF -ve presentation
- constitutional manifestations (low grade fever, malaise, weight loss)
- hepatosplenomegaly
- mild anaemia
- growth abnormalities
- symmetric largevand small joints affection
Polyarthritic JIA RF +ve
- 10% of JIA
- age: 12-16 years
- girls>boys
Polyarthritic JIA RF +ve presentation
- constitutional manifestations (low grade fever, malaise, weight loss)
- anaemia
- nodules
- similar to adult RA but in a child
- erosions in X-ray occur early
Systemic onset JIA
- least common
- most serious short and long term morbidity and mortality
- age: 4-6 years
- girls>boys
- extra-articulate features define the disease
- fever
- rash
- lymph nodes
- abdominal
- serositis
- pulmonary
- arthritis
Systemic onset JIA fever
- rises to 39.5C 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 and chills but looks normal when fever goes away
Systemic onset JIA rash
- 90%
- evanescet salmon red eruptions
- on truck and thighs
- accompanies fever
- can be brought by scratching (+ve Kowbner’s phenomenon)
Systemic onset JIA lymph nodes
- 50-75%
- generalised lymphadenopathy
- non tender
Systemic onset JIA abdominal
- hepatosplenomegaly
- 50-75%
- abdominal pain
- +/- transaminases
Systemic onset JIA serositis
- polyserositis
- pericarditis in 36%
- tamponade and myocarditis rare
Systemic onset JIA pulmonary
- rare
- pleural effusion
- pulmonary fibrosis
Systemic onset JIA arthritis
- 75%
- within 3-12 months of onset of fever
- wrists, knees, ankles, cervical spine, hips and TMJ
Uveitis
- JIA most common cause of non-infectious cause of uveitis
- can affect all JIA groups
- 15-24% patients with JIA develop uveitis early in disease course
- screening- important for all JIA
Uveitis first line treatment
- simple pain killers
- NSAIDs
- intra-articular injections
Uveitis second line treatment
-methotrexate
-anti-TNF Rex (all 3) in methotrexate failure
In refractory systemic arthritis:
-IL-1 R-antagonist
-IL-6 antagonist
When should systemic steroids be used?
- limited indications due to serious side effects
- systemic JIA
- serious disease complications with any subtype
- as a bridge between DMARDs
- children undergoing surgery
- risk of osteoporosis
JIA rehabilitation
- physiotherapy
- occupational therapy
Localised growth failure
- leg length discrepancies
- shortening of fingers, hands, forearms, toes, feet
- micrognathia
Generalised growth failure
- relate to severe systemic disease
- short stature
- delayed puberty
- systemic steroids
