juvenile idiopathic arthritis

Juvenile Idiopathic Arthritis

Prepared By: Mays Husam Nairat

Supervised By: Dr. Maysa Alawnih

Objectives

1. Introduction

2. Etiology

3. Epidemiology

4. Clinical Presentation

5. Classification

6. Diagnosis

7. Complications

8. Prognosis

20/12/2015 2 JIA- Mays Nairat

Introduction

• JIA is one of chronic arthritides of childhood

• Juvenile Idiopathic Arthritis = Juvenile Chronic Arthritis = Juvenile Rheumatoid Arthritis

• JIA includes groups of diseases that share specific characteristics

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Etiology

• It is an autoimmune disease of unknown etiology

• The common underlying manifestation is the presence of chronic synovitis


Epidemiology

• JIA is the most common chronic rheumatologic disease of childhood

• Prevalence 1:1000

• Two peaks; one at 1-3 yrs & one at 8-12 yrs

• Girls are affected more commonly than boys


Clinical Presentation

•onset of the arthritis is slow •the actual joint swelling is often noticed acutely •confused with trauma


• Pain and stiffness in the joint that limit use, but rarely refuses to use the joint at all

• Morning stiffness and gelling (stiffness after rest)


on physical examination :

• Signs of inflammation; joint tenderness, erythema, and effusion

• Joint range of motion may be limited because of pain, swelling, or contractures from lack of use

• Localized growth disturbances

• Leg length discrepancy if arthritis is asymmetrical


Eighteen-month-old girl with arthritis in her right knee. Note the flexion contracture of that knee.


• All children with chronic arthritis are at risk for chronic iridocyclitis or uveitis

• Association between uveitis and HLA-DR5/ DR6/ DR8

• Positive ANA at higher risk for chronic uveitis


Highest risk group:

young girls,

With oligoarticular JIA (less than 5 joints affected),

And Positive ANA

Incidence of uveitis 80%


Classification

1. Oligoarticular JIA

2. Polyarticular JIA

3. Systemic-Onset JIA

4. Spondyloarthropathies


Oligoarticular JIA

• Arthritis in fewer than five joints within 6 months of diagnosis

• The most common form of JIA, 50%

• Two peaks; one at 1-3 yrs & one at 8-12 yrs

• Medium-sized to large joints; knee> ankle > wrist


Oligoarticular JIA

• Children may be otherwise well without any evidence of systemic inflammation (fever, weight loss, or failure to thrive) or any laboratory evidence of systemic inflammation (elevated WBC count or ESR)

Extended Oligoarthritis: Later development of polyarticular disease


Polyarticular JIA

• Children with arthritis in five or more joints within the first 6 months of diagnosis

• 40% of JIA

• Symmetric arthritis, which can affect any joint but typically involves the small joints of the hands, feet, ankles, wrists, and knees


Polyarticular JIA

• The cervical spine can be involved

• Systemic inflammation manifestation; malaise, low-grade fever, growth retardation, anemia of chronic disease

• Elevated markers of inflammation

• Can present at any age; however, there are 2 peaks: in early childhood (RF –ve) and adolescence (RF +ve)



•Patient with active polyarticular arthritis. Note swelling (effusions) of all PIP joints in addition to boney overgrowth. •The patient has interosseus muscle wasting •Subluxation and ulnar deviation of the wrists are present

Systemic-Onset JIA (Still’s disease)

• 10% of JIA

• They does not present with onset of arthritis

• Manifest with a typical recurring, spiking fever, usually once or twice per day, for several weeks to months

• accompanied by a rash, typically morbilliform and salmon- colored - Evanescent, occurs at time of high fever only


Systemic-Onset JIA

• Internal organ involvement also occurs

• Hepatosplenomegaly, 70%

• Serositis, 50%

• Significant constitutional symptoms

• Laboratory findings of inflammation

• The arthritis of JIA follows the systemic inflammation by 6 wks- 6 mo


Spondyloarthropathies

• Inflammation of the axial skeleton and sacroiliac joints and enthesitis (inflammation of tendinous insertions)

• These include:

1. Juvenile ankylosing spondylitis

2. Psoriatic arthritis

3. Arthritis of inflammatory bowel disease


Spondyloarthropathies

• Frequent presence of HLA-B27

• Need earlier Tx with TNF blockers

• They can present with peripheral arthritis, so initially classified in other subgroups

• It is only later when the Dx becomes clear


Workup

• CBC

• ESR, CRP

• ANA

• RF

• Diagnostic arthrocentesis: The synovial fluid WBC

count is typically less than 50,000 to 100,000/mm3, predominantly lymphocytes. Gram stain and culture should be negative.


• The most common radiologic finding in the early stages of JIA is ……………………..….


Normal bone x-ray

• Over time, periarticular osteopenia, resulting from decreased mineralization, is most commonly found


•Severe loss of cartilage. •Boney ankylosis involving the lateral 4 carpal bones with sparing of the pisiform. •Erosions are present in the distal radius and ulna. •Narrowing of the carpal/metacarpal joints is present.


Ankylosis in the cervical spine at several levels due to long-standing JIA

Diagnosis

• The diagnosis of JIA is established by the presence of arthritis, the duration of the disease for at least 6 weeks, and exclusion of other possible diagnoses

• Children must be younger than 16 y/o at time of onset of disease


Treatment

1. Suppressing inflammation

2. Preserving and maximizing function

3. Preventing deformity

4. Preventing blindness


Prognosis

• The prognosis of JIA is excellent, with an overall 85% complete remission rate

• Children with oligoarticular JIA tend to do well

• Children with polyarticular disease and systemic-onset disease constitute most children with functional disability


• The importance of physical & occupational therapy cannot be overstated because when the disease remits, the physical limitations remain with the patient into adulthood


juvenile idiopathic arthritis

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