Arthritis is often associated with older people, but it can also affect children.

In the UK, about 15,000 children and young people are affected by arthritis.

Most types of childhood arthritis are known as juvenile idiopathic arthritis (JIA).

JIA causes pain and inflammation in 1 or more joints for at least 6 weeks.

Although the exact cause of JIA is unknown, the symptoms often improve as a child gets older, meaning they can lead a normal life.

The main types of JIA are:

Oligo-articular JIA

Oligo-articular JIA is the most common type of JIA. It affects up to 4 joints in the body, most commonly in the knees, ankles and wrists.

Oligo-articular JIA often goes away without causing long-term joint damage.

But there’s a risk that children with the condition may develop eye problems, so regular eye tests with an eye care specialist called an ophthalmologist are recommended.

Polyarticular JIA (polyarthritis)

Polyarticular JIA, or polyarthritis, is the second most common type of JIA and affects 5 or more joints.

It can affect a child of any age and may come on suddenly or develop gradually.

The symptoms of polyarticular JIA are similar to the symptoms of adult rheumatoid arthritis.

A child with the condition may also feel unwell and may occasionally have a high temperature of 38C or above.

Systemic onset JIA

Systemic onset JIA begins with symptoms such as a fever, rash, a lack of energy and enlarged glands. Later on, joints can become swollen and inflamed.

Like polyarticular JIA, systemic onset JIA can affect children of any age.

Enthesitis-related arthritis

Enthesitis-related arthritis is a type of juvenile arthritis that often affects the joints of the leg and spine, causing inflammation where the tendons attach to the bone.

It can cause stiffness in the neck and lower back in the teenage years.

It’s also linked to a painful eye condition called acute uveitis.

Versus Arthritis has more information about the different types of juvenile idiopathic arthritis.