What is transient synovitis?

Transient synovitis, also called toxic synovitis, is a disease that affects children (especially between three and eight years) and causes pain in the hip or groin area and weakness. It is caused by virus that causes inflammation of the synovial membrane, which surrounds the hip joint. Transient synovitis is more common in boys than in girls.

What are the symptoms of transient synovitis of the hip?

The main symptoms that may appear are:

• hip pain (on one side)
• weakness
• knee pain
• pain in the thigh, in the front part and towards the middle
• low-grade fever

Infants with the condition may cry more than normal, especially when moving their hip joints, and may be unwilling to crawl.

How is transient synovitis diagnosed?

Diagnosis begins with a medical examination where the GP will assess what movements bring on the pain. They may also carry out blood tests or scans such as X-rays. There are a number of conditions which can cause hip pain in children, so it is important to rule out more serious causes such as septic arthritis or Lyme disease.

What is the treatment for transient synovitis of the hip?

The virus that causes transient synovitis is usually self-limiting so the symptoms will subside over time, usually within 2-5 weeks. You should also look out for potential complications, such as worsening fever, or pain that lasts longer than 4-5 weeks.

In the meantime, you can help manage the pain by:

• encouraging your child to get plenty of rest and avoid contact sports
• getting a prescription of anti-inflammatory medication