Irritable hip happens when the lining of the hip joint becomes inflamed. It is a common cause of hip pain and limping in children under the age of 10 years.
Also known as acute transient synovitis or toxic synovitis, irritable hip is most likely to occur between the ages of 3 and 10 years. It is also more common in boys than in girls.
The tissues around the hip joint swell, normally in one hip only, and pain may spread from the hip to the groin, thigh, and knee. The symptoms may be alarming, but it is a mild condition that normally only lasts up to 2 weeks.
It often appears about 2 weeks after a viral illness, but experts do not know exactly why it happens.
Fast facts on irritable hip:
Here are some key points about irritable hip. More detail is in the main article.
Irritable hip mostly affects children, causing pain that can range from mild to severe.
It can occur after a virus or a trauma, or because of poor blood flow.
It usually passes after 2 weeks, but sometimes it lasts longer.
If the pain persists or gets worse, tests may be needed to rule out other conditions.
Irritable hip is a transient condition in children that causes pain and a limp.
Irritable hip involves hip pain that tends to start suddenly, usually on one side of the hip. The pain can range from mild to severe. It can affect the hip, the groin, the thigh, and the knee on the affected side.
A limp can develop, and young infants may crawl or cry in an unusual way because of the pain. This may be more noticeable when changing diapers.
A slight fever sometimes occurs, but this is less common. If the fever is above 101 degrees Fahrenheit, it is likely the child has another problem, which may be more serious.
In acute, transient synovitis, the synovial membrane that surrounds the hip becomes inflamed or swollen, but it is not clear why this happens.
Possible explanations include: