Transient synovitis of the hip in children.

Transient synovitis is the most common cause of acute hip pain in children three to 10 years of age. Children with this condition typically present with hip pain for one to three days, accompanied by limping or the refusal to bear weight. Transient synovitis has an uncertain etiology and remains a diagnosis of exclusion. First, septic arthritis must be ruled out, since femoral head destruction, degenerative arthritis and permanent deformity can occur if septic arthritis is not treated promptly. Septic arthritis should be suspected in a patient with severe pain or spasm on hip movement or palpation, a temperature higher than 37.5 degrees C (99.5 degrees F) and an erythrocyte sedimentation rate of 20 mm per hour or greater. Hip aspiration is the diagnostic procedure of choice if septic arthritis is suspected. Treatment of transient synovitis consists of bed rest and nonsteroidal anti-inflammatory drugs, with regular temperature checks to exclude the onset of fever. If significant pain and limping persist seven to 10 days after the initial presentation, the patient should be reevaluated.