There is no single test to diagnose JIA in young people. Since arthritis may be a part of many different illnesses, it is important to exclude those other conditions. Your doctor will do a complete evaluation to make sure your joint pain and swelling are not due to some other cause. It may take some time for your doctor to make sure that you have JIA. Your doctor will also need to determine what type of JIA you have.
History
Your doctor will ask you many questions about what has been going on with you. This is to obtain a complete history about your health and symptoms. The doctor will ask about your past health, tests that have been done, medications or treatments that you have used, and how well these treatments worked for you. This health history helps determine how long your symptoms have been present. It can also help rule out other possible causes of joint pain and swelling.
Your doctor will want to know if your parents or other family members have JIA. Some forms of JIA can be inherited, meaning that they can be passed down from generation to generation.
Physical exam
Your doctor will do a complete physical examination, which is an examination of your entire body. During the exam, they will check to see if your joints are inflamed. Symptoms of joint inflammation may include joint swelling, limited movement, or pain on movement.
Certain types of JIA are associated with rash, eye problems, or inflammation of the internal organs. Your doctor will check for these during your physical exam. You may also need to see an eye doctor for a more specialized eye exam.
Blood tests
Your doctor will probably order lab tests. These may include:
- Complete blood count (CBC)
- Erythrocyte sedimentation rate (ESR)
- C-reactive protein (CRP)
- Antinuclear antibody (ANA)
- Rheumatoid factor (RF)
- Human leukocyte antigen B27 (HLAB27)
- Urinalysis
- Other tests if needed (e.g., lyme test).
These blood tests are explained in detail in the article "Blood tests and JIA."
Imaging studies
Your doctor may order imaging studies to help make the diagnosis. Imaging studies provide pictures of your bones, joints, and organs. They can help check for other possible causes of joint pain and swelling. Examples include:
- X-rays
- Ultrasound
- Magnetic resonance imaging (MRI)
- Bone scan and bone density test.