Toxic synovitis is a condition affecting children that causes hip pain and limping.
Synovitis - toxic; Transient synovitis
Toxic synovitis occurs in children before puberty. It is a type of inflammation of the hip. Its cause is not known. Boys are affected more often than girls.
Symptoms may include:
- Hip pain (on one side only)
- Thigh pain, in front and toward the middle of the thigh
- Knee pain
- Low-grade fever, less than 101°F (38.33°C)
Aside from the hip discomfort, the child does not usually appear ill.
Exams and Tests
Toxic synovitis is diagnosed when other more serious conditions have been ruled out, such as:
- Septic hip (infection of the hip)
- Slipped capital femoral epiphysis (separation of the ball of the hip joint from the thigh bone, or femur)
- Legg-Calve-Perthes disease (disorder that occurs when the ball of the thigh bone in the hip does not get enough blood, causing the bone to die)
Tests used to diagnose toxic synovitis include:
Other tests that may be done to rule out other causes of hip pain:
Treatment often includes limiting activity to make the child more comfortable. But, there is no danger with normal activities. The health care provider may prescribe nonsteroidal anti-inflammatory drugs (NSAIDS) to reduce pain.
The hip pain goes away within 7 to 10 days.
Toxic synovitis goes away on its own. There are no expected long-term complications.
When to Contact a Medical Professional
Call for an appointment with your child's 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
Herring JA. Arthritis. In: Herring JA, ed. Tachdjian's Pediatric Orthopaedics. 5th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 26.
Sankar WN, Horn BD, Wells L, Dormans JP. The hip. In: Kliegman RM, Stanton BF, St. Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics. 20th ed. Philadelphia, PA: Elsevier; 2016:chap 678.
Reviewed By: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.