Juvenile Idiopathic Arthritis Flashcards
What is juvenile idiopathic arthritis?
A group of systemic inflammatory disorders affecting children below the age of 16
What kind of disease is JIA?
Autoimmune
Causes of JIA
Genetic
Environmental
Immunologic
Criteria for diagnosis of JIA
- age of onset < 16 y/o
- Duration of disease > 6 weeks
- Presence of arthritis i.e. joint swelling or 2 of the following
- painful or limited joint movement
- tenderness
- warmth
After 6 months, what 3 types of JIA can be identified?
Pauciarticular (55%)
Polyarticular (25%)
Systemic onset (20%)
Which type of JIA is most dangerous?
Systemic onset
Clinical subtypes of JIA
Enthesopathy related arthritis
Juvenile psoriatic arthritis
Others
Features of paucarticular JIA
4 or less joints
3 types
Features of type I paucarticular JIA
Mainly LL joints Knee > ankle > hand or elbow (hip very rare) 1-3 years peak - up to 5 y/o G > B 8:1 - presents in girls \+ ANA in 40-75%
Presentation of type I pauarticular JIA
Limp rather than pain
abnormal gate
systemically fine
What is ANA?
A marker of autoimmune connective tissue disease in adults
+ve ANA in type I pauarticular JIA means they are at risk of what?
Chronic uveitis in 20% (95% if < 2 y/o)
Asymptomatic in 50%
Irregular iris due to posterior synachaeia
Features of type II pauarticular JIA?
> 8-9 y/o
G < B 1:7 - presents In boys
Those with HLA-B27 and back involvement will be categorized as what?
Juvenile ankylosing spondylitis
Presentation of type II pauarticular JIA
Acute iridocyclitis in 10-20% Mainly LL joints Constitutional symptoms rare Asymmetrical UL + LL arthritis Dactylitis Hips can have rapid damage early on requiring THR early in life and entesitis and many have sacroiliac joints and may involve AS or spondyloarthritis
Features of Type III paucarticular JIA
Boys and girls
FH of psoriasis in 40% +/- nail pitting
- these patients may develop psoriasis later on in life
Chronic iridocyclitis in 10-20%
Extended oligoarthritis (30% develop this)
Features of polyarticular JIA
5 or more joints
Second most common type
Two types
2 types of polyarticular JIA
RF -ve
RF +ve
features of RF -ve polyarticular JIA
JIA
Any age, often early
G > B 9:1
Presentation of RF -ve polyarticular JIA
Idiocyclitis rare Growth abnormalities Constitutional manifestations - low grade fever - malaise Hepato-splenomegaly Mild anaemia Symmetric large and small joints affected - knees - wrists - ankles - MCP Iridycitis rare
Features of RF +ve polyarticular JIA
Late childhood/teens (12-16 y/o)
F > M 7:1
Similar to adult RA but in a child
Presentation of JIA
Erosions in X ray occur early Constitutional symptoms - low grade fever - malaise - weight loss Anaemia Nodules iridiocyclitis rare
RF +ve JIA polyarticular can be complicated by….
Sjogrens Felty vasculitis AR pulmonary fibrosis AAS CTS
Features of systemic onset JIA
Less common
Extra-articular features define the disease
- start early and disappear after 2-5 years
4-6 y/o
G > B 1.5:1
Presentation of systemic onset JIA
fever - rise to 39.5C daily for at least 2 weeks - persistent - late in afternoon and evening and returns to (sub)normal in the morning Rash (90%) - evanescent salmon red - on trunk and thighs - accompanies fever and goes when fever goes - can be brought on by scratching (+ve kobeners phenomenon) Lymph nodes (50-75%) - non tender - generalised lymphadenopathy Abdominal - pain - hepatosplenomegaly - +/- transaminases arthritis (75%) - within 3-12 months of onset of fever - Wrists, knees, ankles, cervical spine
Diagnosis of JIA
NO DIAGNOSTIC TESTS
ESR often elevated
- very high in systemic JIA, does not correlate with disease activity
ASO
- often elevated with no evidence of strep infection
RF - 15-20% of children have late onset
ANA: 40-60% of pauarticular JIA
Treatment of JIA
1st line
- simple painkillers
- NSAIDs
- steroids I/A
2nd line (if first lines dont work)
- methotrexate
- anti-TNF (If methotrexate doesn’t work)
- IRL R-antagonist (for refractory systemic arthritis)
- IL-6 antagonist (for refractory systemic disease)
Systemic steroids
- limited indications due to S/Es
Local steroids (Intrarticular/oligoarticular JIA)
Topical steroids (rehab)
Surgery (synovectomy, joints replacements)
When are steroids used?
Systemic JIA (control pain and fever)
Serious disease complications e.g. pericardial effusion, tamponade, vasculitis
As a bridge between DMARDs
Children undergoing surgery
Risks of steroid use in children
Osteoporosis
Infections
Growth abnormalities
