What Is Toxic Synovitis?

What is toxic synovitis?

Toxic synovitis, also known as transient synovitis, is the cause of the most inflammation in a joint. It is more common in young children and is frequently confused with a form of septic, or infectious arthritis. While the cause is unknown, it tends to affect children between 3 years old and 8 years old, with boys more likely than girls to develop toxic synovitis. It usually only affects one joint. While it can occur in the shoulder, ankle, and fingers, it most often affects the hip.

How do you know if your child has toxic synovitis?

In most children with toxic synovitis, the onset of symptoms is sudden. Signs of toxic synovitis may include:

* Pain in one joint, usually a hip or knee.

* A limp or refusal to walk or bear weight on one leg.

* Warmth and swelling around the affected joint.

* Tenderness to the touch.

* Decreased range of motion in the affected joint.

* Fever, although not all children have a fever.

* In children old enough to talk, difficulty walking or pain in the groin, but not necessarily in the affected joint.

Most parents first suspect a muscle pull or sprain; however, if the limp persists, parents may seek medical attention. Once a child is taken to the doctor for evaluation, the physician may order blood work and an X-ray to rule out infection.

How is toxic synovitis treated?

Although toxic synovitis is not caused by an infection, it can mimic septic (infectious) arthritis, which requires more aggressive treatment. Thus, the initial approach to treatment is similar. The goals of treatment are to reduce inflammation and preserve joint function. In most cases, treatment involves one or a combination of the following:

* _Immobilization:_ Keeping the joint still or using a brace can help to reduce movement, minimize pain, and protect the joint.

* _Anti-inflammatory medication:_ Non-steroidal anti-inflammatory drugs (NSAIDs) help reduce inflammation, fever if present, and pain.

* _Physical therapy:_ Physical therapy may be used to strengthen muscles around the affected joint and help restore flexibility and range of motion.

What is the typical course of toxic synovitis?

The symptoms of toxic synovitis usually improve within a few days to a few weeks. Although symptoms may resolve quickly, the joint can be painful and tender for several months. Most children recover fully without any long-term effects.

What is the outlook for a child with toxic synovitis?

Most cases of transient synovitis are mild, and the symptoms resolve within a few weeks. It is rare for toxic synovitis to cause any permanent joint damage.