TRANSIENT MONOARTICULAR SYNOVITIS

TRANSIENT MONOARTICULAR SYNOVITIS

Transient synovitis, also known as toxic synovitis, is a common cause of limping in children. It is a diagnosis of exclusion, because septic arthritis and osteomyelitis of the hip must be excluded

Etiology and Epidemiology
The etiology of transient synovitis is uncertain, but possible causes are viral illness and hypersensitivity. Approximately 70% of children diagnosed with transient synovitis have an upper respiratory tract viral infection in the preceding 7 to 14 days. Biopsies have revealed nonspecific synovial hypertrophy. Hip joint aspirations, when necessary, are negative for bacterial culture or signs of bacterial infection. 
The mean age at onset is 6 years, with a range of 3 to 8 years. It is twice as common in male children.

Clinical Manifestations and Evaluation
The patient or family will describe an acute onset of pain in the groin/hip, anterior thigh, or knee. Irritation of the obturator nerve can cause referred pain in the thigh and knee when the pathology is at the hip. Patients with transient synovitis are often afebrile, walk with a painful limp, and have normal to minimally elevated white blood cell count and erythrocyte sedimentation rate compared with bacterial diseases of the hip (Table 199-1). Table 197-3 lists the differential diagnosis of a limping child. 
Anteroposterior and frog-leg radiographs of the hip are usually normal. Ultrasonography may reveal a small joint effusion. A bone scan may help differentiate transient synovitis from a septic process. 

Differences Between Bacterial Infection and Transient Synovitis 
Bacterial Infection* Transient Synovitis 
Septic arthritis 
Osteomyelitis of hip 
Fever-temperature >38.5 °C Afebrile 
Leukocytosis Normal WBC count 
ESR >20 mm/hour Normal ESR and CRP 
Refusal to walk Painful limp 
Hip held in external rotation, abduction, and flexion Hip held normally 
Severe pain and tenderness Moderate pain and mild tenderness

*Examples: Septic arthritis, osteomyelitis of hip.
CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; WBC, white blood cell. 

Treatment 
The mainstay of treatment is bed rest and minimal weight bearing until the pain resolves. Nonsteroidal anti-inflammatory medication is usually sufficient to decrease pain. Limiting strenuous activity and exercise for 1 to 2 weeks following recovery is helpful. Follow-up will help ensure that there is no deterioration. Lack of improvement necessitates further evaluation for more serious disorders.


মন্তব্যসমূহ