What is a characteristic symptom of a child with septic arthritis compared to transient synovitis?

A characteristic symptom of a child with septic arthritis compared to transient synovitis is joint swelling. In septic arthritis, the joint is often not only swollen but also exhibits significant redness and warmth due to the acute inflammatory process triggered by an infection. This swelling is more pronounced than what is typically seen in transient synovitis, where inflammation may occur, but not to the same extent or with the same urgency.

While joint movement restriction is common in both conditions, it is often more severe in septic arthritis due to the pain and inflammation caused by infection. The presence of fever is also frequently associated with septic arthritis as the body responds to the infection. Recent infections may lead to or be a finding related to both conditions, but they are not definitive characteristics. Therefore, joint swelling stands out as a hallmark symptom that helps differentiate septic arthritis from transient synovitis in pediatric patients.