Irritable hip is a common childhood condition that causes symptoms such as hip pain and limping.
Doctors sometimes refer to irritable hip as transient or toxic synovitis.
Pain isn’t usually severe, but your child may be reluctant to place weight on the affected leg.
Occasionally, an irritable hip may also cause:
- pain in the knee or thigh
- restricted movement in one of the hip joints
- a slightly higher temperature than normal – normal temperature is around 37ºC (98.6ºF)
In younger children who are unable to speak, the only noticeable symptom may be them crying at night.
When to see a doctor
Although irritable hip is usually a mild condition, you should take your child to see a doctor if you are concerned about their hips so that a diagnosis can be confirmed.
This is because irritable hip shares the initial symptoms of more serious hip conditions such as a hip fracture or septic arthritis (an infection inside the hip).
Your doctor will examine their hip and may recommend further tests to rule out other causes. These tests include:
- an X-ray to see if there’s a problem with your child’s bones
- blood tests to look for a bone or joint infection
- an ultrasound scan that will highlight any fluid that may be on the joint
If there’s fluid on the joint, a sample can be removed and checked for an infection.
What causes irritable hip?
The condition develops when the lining that covers the hip joint (the synovial membrane) becomes irritated and inflamed, although the cause of inflammation is unclear.
Some cases of irritable hip occur following a viral infection in the chest, throat or digestive system. Many experts think the synovial membrane in the hip becomes inflamed as a complication of the infection. However, there is no hard evidence to support this theory.
Another theory is that a hip injury may cause the swelling, although many cases develop in children who do not have a history of injury.
Who is affected?
Irritable hip can affect boys and girls of any age. However, the condition affects twice as many boys than girls. It’s most often seen in boys aged 4-10.
Is it serious?
As a parent, it can be very worrying if your child is diagnosed with irritable hip and is struggling to walk. However, if the condition does not get any better, see a doctor.