Juvenile Idiopathic Arthritis Flashcards
What is juvenile idiopathic arthritis?
Juvenile idiopathic arthritis is a group of systemic inflammatory disorders affecting below the age of 16. They are the most commonly diagnosed rheumatic diseases in children and are and important cause of disability and blindness
What are the causes of juvenile idiopathic arthritis?
Genetic
Immunology
Environmental triggers
What is the criteria for diagnosis of juvenile idiopathic arthritis?
<16 years of age
Symptoms present for >6 weeks
Joint swelling or two of; painful or limited joint motion, tenderness or warmth
What are the three types of juvenile idiopathic arthritis, from most to least common?
Pauciarticular
Polyarticular
Systemic onset
What are the characteristics of type I pauciarticular juvenile idiopathic arthritis?
Affects no more than four joints
Mainly lower limb joints but hip very rare
Age: before 5 years, peak 1-3 years
Girls>boys = 8:1
Presentation: limp rather than pain
No constitutional manifestations
Chronic uveitis in 20% of cases (95% if female < 2years old)
Asymptomatic in 50%
Irregular iris due to posterior synechiae
+ve ANA in 40-75%
What are the characteristics of type II pauciarticular juvenile idiopathic arthritis?
Age: after 8-9
Boys>Girls= 1:7
-Mainly lower limb joints: knee, ankle.
Hip can be affected early
20% difficult to classify to particular spondyloarthropathy group.
Presentation: constitutional rare, limp due to LL affection
Acute iridocyclitis in 10-20%.
What are the characteristics of type III pauciarticular juvenile idiopathic arthritis?
Age: any age during childhood Girls> boys = 4:1 Presentation; (constitutional rare, asymmetric UL and LL arthritis, dactylitis) Arthritis can be very destructive Family history of psoriasis in 40% \+/- nail pitting These patients may develop psoriasis later in life Chronic iridocyclitis in 10-20%.
What is dactylitis?
Common side effect of juvenile idiopathic arthritis that is characterised by psoriatic nail changes and “sausage toe”
What are the characteristics of rheumatoid factor positive polyarticular juvenile idiopathic arthritis?
Age: late childhood (teens, 12-16 years) Girls> boys = 7:1 Presentation: -Constitutional manifestations (low grade fever, malaise, weight loss) -Anemia -Nodules. Similar to adult RA but in a child Erosions in x ray occur early Iridocyclitis rare.
What are the characteristics of rheumatoid factor negative polyarticular juvenile idiopathic arthritis?
Age: any age, often early Girls> boys = 9:1 Presentation: -Constitutional manifestations (low grade fever, malaise) -Hepato-splenomegaly -Mild anemia -Growth abnormalities Iridocyclitis rare. Symmetric large and small joints affection: knees, wrists, ankles, MCPs, PIPs, neck, TMJ
How is systemic onset idiopathic juvenile arthritis characterised?
Age: throughout childhood (4-6 years) Girls>boys = 1.5:1 -Pleural effusion -Pulmonary fibrosis -Polyserositis -Pericarditis -Tamponade and myocarditis rare -Undulating fever -Wrists, knees, ankles, cervical spine, hips and TMJ. -Hepatosplenomegaly -Abdominal pain -Generalized non-tender lymphadenopathy -Evanescent salmon red eruption on trunk and thighs that accompanies fever
Why should care be taken when assessing joint mobility in children?
Hypermobility is common in children and so what looks like a normally extended joint might be a joint in which there has been loss of hyperextension due to JIA
Why do patients with IJA require annual ophthalmology screening?
IJA is most common non-infective cause of uveitis and all groups of IJA can be affected by uveitis
What are the possible complications of uveitis?
- Posterior synechiae
- Cataract
- Band keratopathy
How is uveitis treated?
- Steroids: Topical / intraocular / systemic
- Mydriatic & cycloplegic agents
- Methotrexate
- MMF
- Ciclosporin
- Anti-TNF
Describe the treatment of juvenile idiopathic arthritis
1st line treatment of IJA involves NSAIDs and simple painkillers. 2nd line treatment should be started if there is no response to NSAIDs and is as follows:
- 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.
Rehabilitation involving physiotherapy and occupational therapy also useful
When should systemic steroids be used?
In the following cases: – 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 possible complications of systemic steroids?
Osteoporosis
Infection
Growth abnormalities
When can local steroids be used in JIA?
Intra-articular-oligo-articular JIA
Eye disease
What surgeries can be useful in JIA?
Synovectomy
Reconstructive/joint replacement
What are the different kinds of growth failure in JIA?
Localised- short fingers, limbs etc
Generalised- short stature, delayed puberty etc
