What is arthritis in children?

Arthritis is the inflammation of the joints. Arthritis commonly affects older people, but can also occur in children. Arthritis in children is also known as juvenile arthritis and occurs in children under 16 years of age.

Joints

A connecting surface or tissue between two bones.

Causes

The cause of arthritis in children is usually an autoimmune disorder. This means that the body's immune system, which normally fights off harmful bacteria and viruses, mistakenly attacks the body's healthy cells and tissues. In the case of arthritis, the immune system particularly attacks healthy joints. The exact reason why the body does this is unclear; however, research indicates that both genetic and environmental factors play a role.

Genetic

Related to genes, the body's units of inheritance or origin.

Immune system

The organs and cells involved in protecting the body against infection.

Joints

A connecting surface or tissue between two bones.

Risk factors

Risk factors associated with juvenile arthritis include being female (it is more common in girls) and having a family history of particular autoimmune conditions, such as anterior uveitis (inflammation of the inner eye), ankylosing spondylitis, inflammatory bowel disease and psoriasis.

Ankylosing spondylitis

A type of inflammatory arthritis that affects the joints of the spine, particularly where the spine attaches to the pelvis.

Inflammatory bowel disease

A group of conditions characterised by chronic, episodic inflammation of the bowels, including Crohn's disease and ulcerative colitis.

Types

There are multiple types of arthritis in children. These include:

Oligoarticular arthritis

Oligoarticular arthritis is when four or less joints are affected in the first six months of the illness. It commonly affects larger joints including elbows, wrists, knees and ankles. It often affects joints on each side of the body differently; for example, the left wrist may be affected but not the right one. There is an increased risk of anterior uveitis, which involves inner eye inflammation. Oligoarticular arthritis affects more girls than boys and can begin at around 2-4 years of age.

Polyarticular arthritis

Polyarticular arthritis is a condition in which five or more joints are affected during the first six months of the illness. Polyarticular arthritis commonly affects the small joints in the hands and fingers, and sometimes the weight-bearing joints including the hips, knees, ankles and feet, often on both sides of the body. There is an association with also developing anaemia, fever or nodules on the elbows. Polyarticular arthritis is more common in girls than boys and can occur between 1-12 years of age.

Systemic arthritis

Systemic arthritis, also known as Still's disease, affects the entire body, including the skin and internal organs. A high fever, chills and skin rash are also common in the early weeks or months of the condition. Systemic arthritis can also cause inflammation of the lining of the lung (pleurisy) or heart (pericarditis), cause an enlargement of the liver or the spleen, or result in swollen lymph nodes. Systemic arthritis is equally common in boys and girls.

Enthesitis arthritis

Enthesitis arthritis, also known as juvenile spondylitis, is a form of arthritis that causes an inflammation of the area where tendons attach to the bones. This condition more commonly occurs in boys and develops later on in childhood or during adolescence.

Psoriatic arthritis

Psoriatic arthritis refers to inflammatory arthritis due to psoriasis, an autoimmune disorder. Skin and joint problems are likely to occur around the same time, usually around 10 years of age. Although symptoms are usually mild, some children may experience severe or disabling problems into adulthood. For example, as the bones are still developing, juvenile psoriatic arthritis can permanently impair growth.

Psoriatic arthritisPsoriatic arthritis causes the breakdown of bone and cartilage. 

Joints

A connecting surface or tissue between two bones.

Lymph nodes

A small organ of the lymphatic system containing many immune cells. Lymph nodes, also known as lymph glands, are the sites where many interactions between immune cells and foreign materials occur.

Spleen

An organ in the abdominal cavity that is involved in filtering out old blood cells and fighting infection.

Signs and symptoms

Symptoms vary between children and can fluctuate between flare-ups, when symptoms are worse, and other times when no symptoms are present. Juvenile arthritis can affect one or multiple joints depending on the type. Common signs and symptoms can include:

  • Joint stiffness (particularly in the morning), swelling or pain;
  • A skin rash around the affected joints;
  • Fever;
  • Fatigue and weight loss;
  • Swollen lymph nodes;
  • Anaemia, and;
  • Swelling of the eye and vision problems.

Arthritis in children causes joint stiffness and swelling.Arthritis is an inflammation of the joints. 

Fatigue

A state of exhaustion and weakness.

Joints

A connecting surface or tissue between two bones.

Lymph nodes

A small organ of the lymphatic system containing many immune cells. Lymph nodes, also known as lymph glands, are the sites where many interactions between immune cells and foreign materials occur.

Methods for diagnosis

Arthritis in children can be diagnosed by your doctor. Your doctor will ask about your child's symptoms, as well as any family history of arthritis conditions. You may also be referred to a specialist (rheumatologist) who looks specifically at conditions relating to the joints. A diagnosis may require numerous tests to eliminate the possibility of other medical conditions. Tests may include:

  • A bone scan, X-rays and ultrasounds, for imaging of the joints and bones;
  • Blood tests, urine tests and joint fluid tests, which can be used to identify a specific type of juvenile arthritis or other conditions that may be present, such as autoimmune diseases, physical injury or infections;
  • Examinations of the eye, to check for any swelling in the eyes;
  • Echocardiogram to check for any inflammation around the heart, and;
  • Magnetic resonance imaging (MRI), which can provide very detailed imaging inside the joints.

Bone scan

A nuclear scan used to detect abnormalities in the bone caused by cancer, arthritis, infection or injury.

Echocardiogram

An ultrasound image of the heart.

Joints

A connecting surface or tissue between two bones.

Magnetic resonance imaging

A type of imaging that uses a magnetic field and low-energy radio waves, instead of X-rays, to obtain images of organs.

Ultrasounds

A scan that uses high-frequency soundwaves to produce images of the body’s internal structures.

X-rays

A scan that uses ionising radiation beams to create an image of the body’s internal structures.

Types of treatment

The aims of treatment for juvenile arthritis are to control any joint damage, control swelling and limit any pain. Your doctor will give suggestions for the best treatment for your child that will aim to maintain a high level of physical ability and a good quality of life. Some treatment options can include medications and physical therapies, splints and sometimes surgery.

Medications

Depending on the type of arthritis, various medications may be prescribed by your doctor. These can include:

  • Non-steroidal anti-inflammatory drugs (NSAIDS), which are used to reduce swelling and pain;
  • Tumour necrosis factor (TNF) blockers, which are used to reduce joint stiffness, swelling and pain;
  • Disease-modifying antirheumatic drugs (DMARDs), such as methotrexate, which are used to slow the disease's progression;
  • Interleukin inhibitors, which can reduce the activity of the disease;
  • Corticosteroids, given intravenously (IV) or orally, can be used to reduce the swelling;
  • Joint injections of corticoids can reduce inflammation in the affected joints, and;
  • Cortisone eye drops to treat uveitis.

Physical therapies

Physical therapies can help to increase the strength of muscles, increase joint flexibility and aid the normal development of the limbs. They can also help to manage pain, as strong muscles can help to support affected joints. Depending on the affected joint, different exercises may be suggested by your doctor or specialist.

Maintenance devices such as splints made of wood or plastic can be moulded around an area to help the movement of joints. They can also prevent joints from becoming stuck in a specific position. In some cases, surgery of the joint may be required.

Corticosteroids

A medication that resembles the cortisol hormone produced in the brain. It is used as an anti-inflammatory medication.

Joint

A connecting surface or tissue between two bones.

Prognosis

There is no cure for the condition; however most cases can be successfully managed using medications. The use of disease-modifying antirheumatic drugs (DMARDs) has been shown to be very useful in slowing disease progression. Children with the condition can experience times of remission, where no symptoms are present, and flare-ups, when symptoms appear.