An in-depth look at Juvenile Arthritis

Types of juvenile arthritis

There are several different types of Juvenile Idiopathic Arthritis, some of which are milder than others. You’ll need to know which type your child has because this will help your osteopath to plan the treatment and give advice.

Juvenile Idiopathic Arthritis presents with arthritic joint pain and, sometimes, other symptoms outside of joints (known as extra-articular symptoms). These include conditions causing eye inflammation and inflammation of the lining of the heart, lungs or abdomen. Juvenile Idiopathic Arthritis may also be associated with fever or symptoms of anaemia (such as feeling tired all the time).

Oligoarthritis – the most common type of Juvenile Idiopathic Arthritis

Oligoarthritis usually presents in children under 6 years old and is more common in girls.

• It affects about two-thirds of children and young people with arthritis and most commonly affects one or both knees.
• This form of arthritis is often mild and often starts with one or two swollen joints causing stiffness and reduced movement but often not much pain.
• It affects typically four or fewer joints
• It is the most likely to go away and leave little or no damage to the child’s joints.
• There is a risk that children with the condition may develop eye problems, so it is recommended that they have regular checks with an ophthalmologist (an eye care specialist).

Polyarthritis – the second most common type of Juvenile Idiopathic Arthritis

Polyarthritis usually presents in pre-school children and those aged 10-13 years and is more common in girls.

• This type of Juvenile Idiopathic Arthritis tends to cause painful swelling in fingers, toes, wrists, ankles, hips, knees, and the neck and jaw.
• It may come on suddenly or can steadily involve more joints over a period of months.
• The child may feel unwell and tired and occasionally develop a slight fever.
• It affects five or more joints
• The symptoms may continue into adult life but it can go into a state where all the symptoms disappear. This is called remission.

Systemic-onset – the rarest type of Juvenile Idiopathic Arthritis

Systemic-onset usually starts before the age of 5 but can affect children of any age.

• In this form of arthritis, joint pain is part of a general illness involving fever, tiredness, rash, loss of appetite and weight loss.
• A high fever often occurs, most often in the afternoon or evening, with a rapid return of the temperature to normal which may last for weeks or even months
• A rash often appears with the fever. The rash is usually a light pink colour and quickly disappears.
• The child may have enlarged glands in their neck, under their arms and around their groin area.
• In the first few weeks there may be no sign of swollen joints, and the diagnosis may be uncertain. Lots of tests may be needed to confirm the diagnosis and this can be a worrying time.
• Arthritis only occurs at the start of the disease in about one third of children but usually develops within a few months. The arthritis usually affects several joints.
• The long-term development of this form of Juvenile Idiopathic Arthritis can be difficult to predict but usually the fever and rash will settle, although the arthritis may sometimes continue for several years before settling.

Enthesitis-related Juvenile Idiopathic Arthritis

Enthesitis-related arthritis tends to affect older boys or teenagers

• This form of Juvenile Idiopathic Arthritis affects the places where tendons attach to the bone (these places are called entheses), causing inflammation.
• It can cause pain in the soles of the feet and around the knee and hip joints where the ligaments attach to the bone.
• Psoriasis, eye inflammation and bowel inflammation may also occur with enthesitis-related Juvenile Idiopathic Arthritis

Juvenile psoriatic arthritis

Psoriasis is a scaly skin rash, and with this you can also get joint pain known as psoriatic arthritis.  This affects girls twice as often as boys and tends to start at about 6 years of age.

• This arthritis usually affects the fingers and toes, but it may affect other joints too.
• Eye inflammation is also fairly common but it’s the painless type that doesn’t look red.
• The joints may be affected before the skin rash appears – your doctor may look closely at the child’s fingernails and toenails for early signs of psoriasis and may ask if anyone in your family has the condition.
• The arthritis affects both small and large joints. In over half of affected children, the arthritis starts before the psoriasis

Undifferentiated arthritis

Sometimes young people don’t fit neatly into the above groups and the condition is defined as undifferentiated arthritis. It may not seem a very useful category, but it’s one that doctors sometimes have to use.

Other Types of Juvenile Arthritis:

• Juvenile Spondyloarthropies (ankylosing spondylitis, seronegative enthesopathy and arthropathy syndrome) are a group of diseases that involve the spine and joints of the lower extremities, most commonly the hips and knees.
• Juvenile Dermatomyositis is an inflammatory disease that causes muscle weakness and a characteristic skin rash on the eyelids.
• Juvenile Systemic Lupus Erythematosus is an auto-immune disease associated with skin rashes, arthritis, pleurisy, kidney disease and neurologic movement.
• Juvenile Vasculitis is an inflammation of the blood vessels and can be both a primary childhood disease and a feature of other syndromes, including dermatomyositis and systemic lupus erythematosus.