Toxic synovitis

Toxic synovitis is an irritation and swelling of the lining of the hip joint. The condition causes pain and tenderness that may move down to the thigh and knee; it sometimes makes a person limp.

Toxic synovitis is the most common cause of hip pain in children. It typically occurs in children between the ages of 3 and 8 years. Toxic synovitis happens more often in boys than in girls. It commonly follows a mild injury or an illness with a fever, such as tonsillitis or an ear infection.

This condition usually resolves on its own, but treatment may be given for pain and inflammation.

Toxic synovitis is also called transient synovitis.