MSK: Juvenile Idiopathic Arthritis Flashcards
It is the most common chronic joint disease in children and adolescence. True or false?
True
How is it defined?
Persistent joint swelling of > 6 weeks presenting before 16 in the absence of infection or any other defined cause
What is the prevalence in the UK?
1 in 1000
How many subtypes are there?
At least 7
How is it classified?
Clinical and based on number of joints affected in first 6 months
- polyarthritis = more than 4 joints
- oligoarthritis = up to and including 4
- systemic = with rash and fever
Presence of rheumatoid factor and HLA B27 tissue type
What features are present?
Gelling - stiffness after periods of rest Morning joint stiffness Painful joints Intermittent limp Deterioration in behaviour or mood
Is there joint swelling?
Initially may be minimal, but subsequently swelling due to fluid within joint, inflammation, chronic arthritis, thickening of synovium and swelling of periarticular soft tissue
Why can diagnosis be difficult initially?
Presentation can be indolent
Initially blood tests normal and x ray
What complications can occur?
Chronic anterior uveitis Flexion contractures at joints Growth failure Constitutional problems - anaemia of chronic disease, delayed puberty Osteoporosis
Why can growth failure occur?
Generalised from anorexia, chronic disease and systemic corticosteroids
Localised overgrowth e.g leg length discrepancy due to prolonged knee synovitis
What is the overall management aim?
Induce remission
Medical management includes:
NSAIDS and analgaesia to relieve symptoms during flare
Joint injections (intra-articulate corticosteroids)
Methotrexate - used early reduces joint damage
Systemic corticosteroids- avoided if possible
Biologics - severe disease refractory to methotrexate