Juvenile Idiopathic Arthritis Flashcards
What is juvenile idiopathic arthritis?
Group of autoimmune diseases causing systemic inflammatory disorders affecting children below the age of 16 years
- Important cause of disability and blindness
What is the criteria for diagnosis of juvenile idiopathic arthritis?
- Being younger than 16 years
- Duration of symptoms longer than 6 weeks
Symptoms include joint swelling OR 2 of the following:
- Painful of limited ROM
- Tenderness
- Warmth
What are the clinical subtypes of JIA?
Oligoarticular / pauciarticular (4 or less joints) - 55% (F»_space;> M)
Polyarticular (5 or more joints) - 25% (F»_space; M)
Systemic onset - 20% (F = M)
Who is type 1 pauciarticular JIA most common in? How does it tend to present? Which antibody is commonly detected in this condition?
Most common in girls < 5yrs
- presents with loss of function more so than pain
- Eyes*: Chronic uveitis +/- irregular iris common
- Don’t tend to have systemic manifestations
- Usually affects lower limbs: Knee > ankle > hand / elbow
- positive for ANA (antinuclear antibody) in 40-75%
Who is type 2 pauciarticular JIA most common in? How does it tend to present?
- Most common in boys older than 8 / 9 yrs
- Usually lower limb affected: knee, ankle, hip (may develop to sacroiliitis / spondyloarthritis)
- Systemic manifestation uncommon
- Iridocyclitis common: inflammation of iris & ciliary body
Who is type 3 pauciarticular JIA most common in? How does it tend to present?
- Most common in girls, any age in childhood
- Asymmetric upper limb or lower limb arthritis +/- dactylitis
- Often associated with psoriasis
- Nail pitting / chronic iridocyclitis common
What is dactylitis?
Severe inflammation of the finger and toe joints
What is extended oligoarthritis?
Possible progression of symptoms for children presenting with pauciarticular JIA (< 4 joints)
- Present with < 4 joints but go on to develop a more severe polyarticular course
- About 30% of oligoarticular JIA cases
What are the two divisions of polyarticular JIA? Who does each tend to affect?
Rheumatoid factor positive: affects mainly girls, between ages of 12-16
Rheumatoid factor negative: affects mainly girls, any age of childhood
How does RF negative polyarticular JIA tend to present?
Symmetric large and small joint polyarthritis: knees, wrists, ankles, MCPs / PIPs, neck
- Systemic manifestations: fever, malaise
- Hepato / splenomegaly
- Mild anaemia
- Restricted growth
How does RF positive polyarticular JIA tend to present?
Presents similarly to adult Rheumatoid Arthritis: Symmetric
- Systemic: fever, malaise, weight loss, Sjogren’s, vasculitis, PF,
- Anaemia
- Nodules
- Bone erosion on X-Ray develops early
What is a common examination that needs to be conducted in children presenting with JIA?
Examination of the eye
Blindness can easily result if eye inflammation is not checked for and treated quickly
Who tends to get systemic onset JIA?
- Any age of childhood (peaks 4-6 years), 1.5:1 F : M
What are some of the common systemic manifestations of systemic onset JIA?
- Fever: rises to about 39.5 each day for 2 weeks, rises late in day & returns to normal in the morning
- Rash in 90%: red eruption on trunk and thighs. Accompanied by fever, can be brought on by scratching
- Non-tender lymphadenopathy
- Hepatosplenomegaly (+/- abdominal pain / raised transaminases)
- Serositis (often pericarditis)
What are the characteristics of the arthritis present in systemic onset JIA?
- Only present in 75%
- Occurs within 3-12 months of fever
- Tends to affect: wrists, knees, ankles, cervical spine, hips and TMJ
- Loss of joint hypermobility
