Suspicion of juvenile arthritis relies on a thorough history and physical examination. There are no specific tests for the diagnosis of juvenile arthritis.

History and physical examination

A strong suspicion of JIA in its early stages is indicated by:

• Persistent pain and swelling of single or multiple joints over several weeks
• Stiffness in the early morning which improves over the day
• Reluctance to use or move affected joint(s) through their full range of movement
• Lack of alternate explanation for the problem such as recent injury or infectious illness

It is important to remember that:

i) Symptoms of JIA are consistent and persistent (symptoms that come and go and are a bit different every time are not likely to be JIA)
ii) Specialist input is critical to early diagnosis and management to achieve disease control and prevent permanent joint and eye damage.

Investigations

• There is no specific test for JIA in children
• FBC, ELFT, ESR and CRP are useful initial tests to help rule out other causes
• A small percentage of children with JIA will have a positive Rheumatoid Factor but the majority will be Rheumatoid Factor negative
• ANA, HLA-B27 test help classify JIA types and determine risk for, and types of, eye involvement but even when present are not diagnostic of JIA
• X-rays are usually not helpful in the early stages of the disease
• Ultrasound can be useful in detecting synovitis but rarely indicates its cause
• A careful history and examination will provide the most useful clues to the diagnosis

What should the GP do if JIA is suspected?

1. Urgent referral to paediatric rheumatologist is required if JIA is suspected or can’t be excluded. See Find a Paediatric Rheumatologist at the top of this page
2. If there is likely to be any delay in specialist assessment of a child with suspected JIA, make an urgent referral to an optometrist for screening for uveitis with a slit lamp.

Uveitis

• A proportion of children with JIA will have uveitis at diagnosis or develop it later
• Uveitis can cause loss of vision up to an including blindness if not detected early and treated effectively.
• Uveitis may be asymptomatic and there may be no obvious changes in the appearance of the affected eye
• Uveitis always requires urgent assessment, and ongoing monitoring and management by an ophthalmologist.