Toxic Synovitis: A-to-Z Guide from Diagnosis to Treatment to Prevention

Introduction to toxic synovitis:

Whenever children develop a limp they should be checked to be sure that the cause is not something that needs emergency treatment, such as septic arthritis. When the results come back, parents will often hear that the diagnosis is toxic synovitis. This sounds like bad news, but it is good news.

What is toxic synovitis?

Toxic synovitis of the hip is the most common form of arthritis in children. It appears suddenly, disappears suddenly, and causes no lasting problems. Thus, it is often called transient synovitis.

It typically follows viral infections, and may be caused by the body’s immune response to the virus. For this reason, it is often called postinfectious arthritis. Many viruses can lead to some type of postinfectious arthritis — including adenovirus, chickenpox, CMV, coxsackievirus, EBV, hepatitis B, herpes, mumps, parvovirus, rubella, and smallpox.

Who gets toxic synovitis?

Toxic synovitis can happen in any child, but it is most common in boys between the ages of 3 and 10, after an upper respiratory tract infection.

What are the symptoms?

Boys usually complain of pain in the hip, thigh, or knee. They suddenly develop a noticeable limp. There is usually no fever, redness, or swelling of the joint.

Is it contagious?

No. The viral infections that lead to toxic synovitis are often contagious.

How long does toxic synovitis last?

Toxic synovitis usually disappears completely within a few days.

How is toxic synovitis diagnosed?

Children with a new limp need to be examined, and some may need to have blood tests and an imaging study to be sure there is not a condition that needs emergency treatment. In toxic synovitis, the blood tests are usually normal.

How is toxic synovitis treated?

Toxic synovitis needs no treatment other than pain relief.

How can toxic synovitis be prevented?

Usually toxic synovitis is not preventable, except by avoiding the viral infections that can trigger it.

Related concepts:

Transient synovitis, Postinfectious arthritis

Related A-to-Z Information:

Adenovirus, Arthritis (Juvenile rheumatoid arthritis, JRA, Chickenpox (Varicella) , CMV (Cytomegalovirus), Cold Sores (Herpes simplex), Common Cold, Congenital Hip Dislocation, Coxsackievirus, Fractures, Hand-Foot-Mouth Disease, Hepatitis B, Herpangina, Human Herpesvirus, Lyme Disease, Mononucleosis (Mono), Mumps, Parvovirus B19, Rheumatic Fever, Rubella (German measles), Scoliosis, Smallpox, Spina Bifida, Sprains, Streptococcus (Strep), Tibial Torsion (Turned-in feet), Torticollis

Dr. Alan Greene

Dr. Greene is the founder of (cited by the AMA as “the pioneer physician Web site”), a practicing pediatrician, father of four, & author of Raising Baby Green & Feeding Baby Green. He appears frequently in the media including such venues as the The New York Times, the TODAY Show, Good Morning America, & the Dr. Oz Show.