Toxic synovitis

• Alternative Names

  Synovitis - toxic; Transient synovitis

• Causes, incidence, and risk factors

  Toxic synovitis occurs in children before puberty begins. It is a type of arthritis of the hip. Its cause in not known, but boys are affected more often than girls (approximately 4 to 1).

• Symptoms

  Symptoms may include:

  • Hip pain (on one side only)
  • Limp
  • Thigh pain, in front and toward the middle of the thigh
  • Knee pain
  • Low-grade fever, less than 101° Fahrenheit

  Aside from the hip discomfort, the child does not usually appear ill.

• Signs and tests

  Toxic synovitis is diagnosed when other, more serious conditions have been ruled out, such as:

  • Septic hip
  • Slipped capital femoral epiphysis
  • Legg-Calve-Perthes disease

  Tests used to diagnose toxic synovitis include:

  • Ultrasound of the hip
  • X-ray of the hip
  • ESR
  • C-reactive protein (CRP)
  • Complete blood count (CBC)

  Other tests that may be done to rule out other causes of hip pain:

  • Aspiration of fluid from the hip joint
  • Bone scan
  • MRI
• Treatment

  Treatment often includes limiting activity to make the child more comfortable. However, there is no danger with performing normal activities. The health care provider may prescribe nonsteroidal anti-inflammatory medications (NSAIDS) to reduce pain.

• Expectations (prognosis)

  The hip pain goes away within 7 - 10 days.

• Complications

  Toxic synovitis goes away on its own. There are no expected long-term complications.

• Calling your health care provider

  Call for an appointment with your child's health care provider if:

  • Your child has unexplained hip pain or a limp, with or without a fever
  • Your child has been diagnosed with toxic synovitis and the hip pain lasts for longer than 10 days, the pain gets worse, or a high fever develops
• References

  Hosalkar HS, Horn D, Friedman JE, Dormans JP. The Hip. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 677.

Review Date: 11/2/2009

Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.