Adults with rheumatoid arthritis (RA) are generally classified during diagnosis as having seropositive or seronegative RA based on the presence of biomarkers found in the blood. Regardless of classification, the symptoms of rheumatoid arthritis tend to be similar.
When children are diagnosed with RA, it is called juvenile RA, juvenile chronic arthritis, or juvenile idiopathic arthritis (JIA). The condition may or may not disappear as the child grows up.
Between 60 percent and 80 percent of people with rheumatoid arthritis are diagnosed as seropositive. If your blood test shows the presence of anti-cyclic citrullinated peptides (anti-CCPs), proteins that provide evidence of an autoimmune reaction, you are considered seropositive. Anti-CCPs can show up in the blood five or even 10 years before RA symptoms appear. Presence of rheumatoid factor (RF) in the blood may also be used in classifying someone as seropositive.
If you are diagnosed with rheumatoid arthritis, but anti-CCPs and RF are not found in your blood, you will be classified as seronegative. People with seronegative RA often have a milder disease course than those with seropositive RA. Sometimes seronegative RA patients can become seropositive, even after many years of RA.
Read more about how RA is diagnosed.
Juvenile RA symptoms are similar to other types of RS, including swelling, pain, and stiffness in the joints. While symptoms may go into remission with age, some children will continue to have RA-related symptoms in adulthood. In addition to the joint symptoms, juvenile RA may also interfere with a child’s growth and bone development or cause inflammation in the eyes or lymph nodes.
There are several subtypes of juvenile RA. Systemic onset juvenile idiopathic arthritis begins with repeated high fevers and a salmon-colored rash. Systemic onset JIA may involve inflammation of the organs in addition to the joints. Oligoarticular JIA involves fewer than five joints, while polyarticular JIA involves five or more joints. Enthesitis-related arthritis, also called spondyloarthritis, involves the spine and ligaments.