Doctors usually suspect juvenile rheumatoid arthritis, along with several other possible conditions, when they see children with persistent joint pain or swelling, unexplained skin rashes and fever, or swelling of lymph nodes or inflammation of internal organs. A diagnosis of JRA also is considered in children with an unexplained limp or excessive clumsiness.
Examination & Tests
No one test can be used to diagnose JRA. A doctor diagnoses JRA by carefully examining the patient and considering the patient's medical history, the results of laboratory tests, and x rays that help rule out other conditions.
Length of Symptoms
One important consideration in diagnosing JRA is the length of time that symptoms have been present. Joint swelling or pain must last for at least 6 weeks for the doctor to consider a diagnosis of JRA. Because this factor is so important, it may be useful to keep a record of the symptoms, when they first appeared, and when they are worse or better.
Laboratory tests, usually blood tests, cannot by themselves provide the doctor with a clear diagnosis. But these tests can be used to help rule out other conditions and to help classify the type of JRA that a patient has.
X rays are needed if the doctor suspects injury to the bone or unusual bone development.
Because there are many causes of joint pain and swelling, the doctor must rule out other conditions before diagnosing juvenile rheumatoid arthritis.