Transient (toxic) synovitis of the hip presents as a limp or a painful hip or pain in the knee (referred pain). It typically affects boys between 3 to 8 years of age. The etiology is unknown. The child is not sick looking and on examination of the hip joint, the affected leg is usually held in a position of external rotation and flexion.
Treatment is NSAIDs and bed rest. This self-limited process tends to resolve within few days. If recovery is delayed or there is any concern for an infection being the cause of hip pain and limp (fever, abnormal ESR or WBC count, localized tenderness), a diagnostic aspiration should be done or preferably should be referred to a pediatric orthopedic surgeon.