Pathologic aspects of juvenile chronic polyarthritis.

The pathological changes in juvenile chronic polyarthritis are similar to those of adult chronic polyarthritis, although perhaps rather more variable, according to the severity and the phase of the disease. The differences that are seen depend on age, developmental stage, growth, and perhaps a greater regenerative capacity. The nodules of seronegative diseases resemble those of rheumatic fever and are not seen in adult onset seropositive rheumatoid arthritis. In addition, ankylosis of the cervical spine is a characteristic feature seen also in adult onset Still's disease.