How to Diagnose Juvenile Arthritis

Diagnosis of juvenile arthritis may be difficult as the symptoms of arthritis can vary and some patients may have symptoms of the associated disease as well. There is no single test that can confirm the diagnosis of juvenile arthritis. Hence diagnosis is made by exclusion of other conditions (such as bone disorders or fractures, fibromyalgia, infection, Lyme disease, lupus, or cancer) which can cause similar symptoms.

Medical history: Your doctor will take a detailed medical history and perform a physical exam to diagnose the cause of pain or other symptoms like refusal to walk, clumsiness. History may include questions regarding location of the pain, time and pattern of the pain, presence or absence of stiffness and any other associated symptoms. Physical examination will include examination of joint (for pain, stiffness, range of motion, deformity, fracture etc.) and other systems.

Laboratory tests: Your child’s doctor after examination may recommend tests to determine the type of arthritis your child has. Some of the tests that might be done include:

• Complete blood count (white cells, red cells, and platelets):The test counts the different number of blood cells (red blood cells, white blood cells, and platelets). It is done to determine if there is an underlying disease or infection which is probably causing your child’s symptoms.
• Other laboratory tests on blood: Blood tests for presence of markers of inflammation such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)may be done. These markers tend to be elevated in cases of juvenile arthritis and they are good indicators of disease activity as well.Blood culture or joint fluid sample for bacteria may be done to rule out infection of the joint or bloodstream
• X-rays of the joint: To detectfracture or damage to bonesor joints. In early stages of the juvenile arthritis the X-ray may be normal
• Magnetic resonance imaging (MRI) scans: Other imaging studies such as MRI or CT scan may be done. They can help in earlier detection of bone erosion and other changes of arthritis than X-rays.
• Immunologic tests: Tests may be done to check for levels of rheumatoid factor (RF), antinuclear antibodies (ANA), and possibly other antibodies. Rheumatoid factor is an antibody that may be present in cases of arthritis (but an abnormal result is more likely in adults than in children). Antinuclear antibody test indicates evidence of autoimmunity and can help to determine if the child with juvenile arthritis is at risk of eye disease.
• Bone scan: The test can help to detect inflammatory changes in bones and joints
• Other tests: Tests to rule out other conditions (such as bone disorders or breaks, fibromyalgia, infection, Lyme disease, lupus, or cancer) which can cause similar symptoms may be done.  These include tests such as tests for viruses, tests for Lyme disease, bone marrow examination to check for leukemia.

These are some of the tests that may be done in a child with juvenile arthritis. Your doctor will not recommend all the tests at the same time. Tests are done based on the signs and symptoms and severity of disease.