diagnosis
Diagnosis of JIA is made through history and physical examination.
- no conclusive laboratory tests are available for the diagnosis
- it is important to exclude other joint problems with a discernable cause
In history inquire about:
- joint pain and swelling and also about similar symptoms prior to this episode
- morning stiffness that lasts for more than 15 minutes but improves during the day
- autoimmune disease in relatives
- specific family history - in suspected psoriatic arthritis and enthesitis related arthritis
- any systemic features e.g. - rash or intermittent pyrexia
- any problems with walking, running, climbing stairs, standing up, writing, or sleeping - specially from parents, other family members, or teachers
- any assistance given to carry out daily activities that were previously performed independently
Physical examination should include:
- examination of all joints for
- pain or tenderness
- swelling
- redness
- limited movement
- decreased strength or muscle atrophy
- bony deformity
- child should be observed while walking, standing up, sitting down, or climbing on to the examination table
- general examination
- lymphadenopathy
- organ enlargement
- systemic rashes
- nail abnormalities
- psoriatic rash, or enthesitis
- growth measurements
- eye examination by ophthalmologists for uveitis
Further investigations which can be carried out for all subtypes include:
- full blood count
- inflammatory markers -erythrocyte sedimentation rate, C reactive protein
- autoimmune markers - rheumatoid factor, HLA B27, and antinuclear antibodies
- imaging studies
- radiography - narrowing of the joint spaces or erosions, maturation differences or growth abnormalities in bones from an early stage
- MRI - inflamed synovium and increased joint fluid
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