Juvenile idiopathic arthritis

This is a type of arthritis which affects children although it tends to be quire rare. It affects 1 to 2 out of 1,000 children and is not to be confused with rheumatoid arthritis.

Most children affected with juvenile idiopathic arthritis or JIA for short make a full recovery. But a small minority are left with constant symptoms or damage to their joints well into their adulthood.

There are three versions of JIA which are:

• Oligoarticular JIA
• Polyarticular JIA
• Systemic onset JIA

These are all discussed in more detail as separate sections within this guide.

The most common type of JIA is oligoarticular JIA. Most children who develop oligoarticular JIA make a complete recovery, but they are at risk of developing eye disease later on in life.

Polyarticular JIA has very similar symptoms to those of rheumatoid arthritis. This is the second most common form of juvenile arthritis.

Systemic onset JIA accounts for the fewest number of cases. This type of JIA is difficult to diagnose accurately and can cause long term problems.

This section discusses juvenile idiopathic arthritis (JIA) as follows:

• Definition of JIA
• Causes of JIA
• Symptoms of JIA
• Diagnosing JIA
• Treatment of JIA

Definition of JIA

Juvenile idiopathic arthritis is defined as a condition in which one or several joints of the body are affected by pain and inflammation. The joints are stiff, have a red appearance and are warm to the touch. Movement is restricted in the affected joint.

The joints feel stiff in the morning but loosen up throughout the day.

JIA affects both boys and girls although a slightly higher percentage of girls are affected.

Causes of JIA

Common theory is that JIA is caused by genetic and environmental factors.

In other words, it may be inherited (although this is rare) or caused by a viral infection such as mumps. JIA may also be caused by the following medical conditions:

• Rubella (German measles)
• Herpes Simplex
• Crohn’s disease
• Haemophilia
• Malignancy
• Cystic fibrosis
• Lupus
• Ankylosing spondylitis

But it appears to be the case that JIA is caused by over activity within the immune system.

Symptoms of JIA

These are similar to many forms of arthritis and include:

• Inflammation
• Pain
• Stiffness
• Heat
• Red appearance around the affected joint
• Raised temperature
• Fatigue
• Skin rash
• Lack of appetite
• Muscle pains

All of these are characteristic of the three variants of JIA. What is often the case is that the child will complain that their symptoms are worse due to changes in temperature. For example their joints are stiff and painful on a cold, wet day.

This is a common feature of many kinds of adult arthritis.

Plus children often report that their joints are stiff when they first get up but ease during the course of the day. Again, this is another common aspect of arthritis in both adults and children.

Diagnosing JIA

It is difficult for a parent to detect signs of JIA. Their child may suffer a loss of appetite, have little energy and is generally, off colour.

If they appear to limp or find it difficult to put any weight on a joint then this may indicate JIA but a formal diagnosis is needed. If your child complains of stiffness in their arms or legs, first thing in the mornings or pains in their joints then this needs to be further investigated.

Consult your GP. Mention about these symptoms to him/her and if anyone else in your family has this condition. If your child has recently been ill with a viral infection such as mumps then mention that as well.

Your GP will ask you (or your child if he/she is old enough) about their symptoms and medical history. He/she will examine your child before referring him/her for tests, e.g. blood tests. X-rays and bone scans may also be carried out.

Treatment of JIA

This depends upon the type of JIA but usually involves drugs such as anti-inflammatories or steroids to reduce pain and inflammation. The affected joint may be put in a splint.

Your child will be encouraged to take exercise and remain as active as possible. This is important as it ensures that they continue to grow and develop.

Physiotherapy is another option. This is ideal for improving strength and flexibility in arthritic joints and can be fun to do as well. Your child may have to see a podiatrist who will advise about foot care and ways of walking to ease pressure on the joints.

Your child will require eye tests as JIA can cause an inflammation of the eye amongst other symptoms. This is known as ‘uveitis’. Regular eye tests with a specialist will needed over a period of several years to prevent any permanent damage to the eyes.