juvenile idiopathic arthritis

Arthritis is a condition that affects the joints. It means one or more of your joints are swollen, painful and stiff (inflamed). Juvenile means the arthritis affects children under 16 years. Idiopathic means the cause is unknown. JIA affects about one in 1,000 children in the UK.

JIA is a chronic condition. A chronic illness is one that lasts a long time, sometimes for the rest of the affected person's life. When describing an illness, the term chronic refers to how long a person has it, not to how serious a condition is.

Types of juvenile idiopathic arthritis

There are three main types of JIA.

• Oligoarticular (or pauciarticular) JIA - the most common type, affecting only a few joints, usually the knees, ankles, elbows or wrists.
• Polyarticular JIA - the second most common type, affecting many joints including fingers and toes.
• Systemic JIA (Stills disease) - the rarest type where joint pain is part of a more general illness.

Symptoms of juvenile idiopathic arthritis

JIA affects all children differently. Symptoms may come and go over time with periods when they flare up and are worse. There may be times when your child has no symptoms at all - this is called remission.

The main symptoms of JIA are swollen, painful and stiff joints. The joint areas may look red and feel hot when you touch them. The exact symptoms and number of joints affected will vary depending on which type of JIA your child has.

Children with polyarticular JIA will have at least five or more joints affected including fingers and toes. Swelling and pain may also occur in hips, neck and jaw. Your child may also have other symptoms such as:

• nodules on their elbows
• a rash
• a fever

As well as joint pain, children with systemic JIA may have:

• a fever
• a rash
• swollen glands
• tiredness and lack of energy
• weight loss

Complications of juvenile idiopathic arthritis

JIA may affect your child's general growth. It's possible that your child's affected limbs may develop at different rates. For example if the arthritis is particularly bad in one knee the affected leg may be slightly shorter.

Anaemia may also be a problem. Anaemia is when there are too few red blood cells or not enough haemoglobin in the blood.

There is also a risk that your child may develop inflammation of the eyes (uveitis). Make sure your child has regular eye checks with an ophthalmologist (a doctor who specialises in eye health), even if he or she doesn't have any obvious symptoms.

There is a risk that systemic JIA may affect internal organs such as the tissue that covers the heart, liver or spleen. Children with systemic JIA may need to have regular check-ups.

Causes of juvenile idiopathic arthritis

The cause of JIA isn't fully understood at present but it's thought to be an autoimmune disease. An autoimmune disease is a condition caused by antibodies from the immune system attacking the body. It's possible that the tendency to develop the condition is inherited. However, it's thought that other factors are likely to be involved which are responsible for setting off this reaction of your child's immune system.

Diagnosis of juvenile idiopathic arthritis

Your GP will ask about your child's symptoms and examine him or her. Your GP may also ask you about your child's medical history.

There is no single test that can diagnose JIA and your GP will want to rule out other conditions that may be causing your child's symptoms. Your GP will usually refer your child to a paediatrician (a doctor who specialises in children's health).

Your child may need to have several tests, such as:

• blood tests to check haemoglobin levels and autoantibodies.
• X-rays, MRI, CT or ultrasound scan to check for any signs of inflammation in the joints or fluid build-up around the heart or lungs

Treatment of juvenile idiopathic arthritis

There isn't a complete cure for JIA, but there are treatments available to help control or ease the symptoms.

Your child will receive treatment from a team of health professionals. He or she will need regular check-ups to monitor his or her condition.

Self-help

Regular exercise such as swimming, running or aerobics may be helpful.

Your child will be given exercises by a physiotherapist to do at home. These will aim to reduce the pain and stiffness in your child's joints. Your child will need to do these exercises every day, even though he or she may not feel like it.

Using heat treatments, such as a hot water bottle wrapped in a towel may help to ease painful and swollen joints. A cold compress, such as ice or a bag of frozen peas, wrapped in a towel may also help. Never apply ice directly to your skin as it can give you an 'ice burn' - always place a cloth between the ice and skin.

Medicines

There are many different medicines available to help control symptoms, slow down or even stop the progression of JIA.

• Non-steroidal anti-inflammatory drugs (NSAIDs) - such as ibuprofen, can help ease pain, stiffness and swelling. For some children with mild JIA, this may be the only medicine they need to take.
• Painkillers - such as paracetamol can help ease joint pain.
• Steroids - such as prednisolone can help ease swelling. Steriods may be given as tablets, injection into a tissue or joint or through a drip into a vein.
• Disease-modifying antirheumatic drugs (DMARDs) - such as methotrexate can ease swelling and slow down the disease process. Most importantly, by controlling arthritis they can help reduce how much steroids your child needs to keep well. It may take up to three months for these medicines to have an effect.
• Etanercept is a new type of medicine and it works by blocking the action of a part of the immune system. Your child may be offered this medicine if other medicines haven't helped.

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