Juvenile chronic arthritis or juvenile idiopathic arthritis (JIA) is long-term joint inflammation (arthritis) in children. It is not one condition, but includes a group of different conditions. To be diagnosed as juvenile idiopathic arthritis, arthritis must begin before age 16, last more than 6 weeks, and not be due to another illness or a known problem
Juvenile idiopathic arthritis (or JIA) is the newer name for this group of conditions. It is also called ‘juvenile chronic arthritis’, ‘juvenile arthritis’, or ‘juvenile rheumatoid arthritis’. ‘Juvenile’ means occurring in childhood. ‘Idiopathic’ means that no cause can be found after a medical checkup, which could include tests. ‘Chronic’ means long-term.
Types of juvenile arthritis
Juvenile idiopathic arthritis is divided into several different conditions, mainly depending on:
- how many joints are affected during the first 6 months – ‘oligoarthritis’ means a child has arthritis in up to 4 joints, and ‘polyarthritis’ means there is arthritis in more than 4 joints.
- whether or not blood tests are positive for rheumatoid factor during the first 6 months – rheumatoid factor indicates that the immune system is attacking the child’s own body. Only a small proportion of children with juvenile idiopathic arthritis test positive for rheumatoid factor.
The types of juvenile arthritis are:
- oligoarthritis – about half of all children with juvenile arthritis have this type.
- polyarthritis (rheumatoid factor negative) – about 10–30% of children with juvenile arthritis have this type.
- polyarthritis (rheumatoid factor positive) – this type is uncommon and usually occurs in older children and teenagers.
- systemic arthritis – (also called Still’s disease) – this type is fairly uncommon. ‘Systemic’ means affecting the whole body, not just joints.
- enthesitis-related arthritis – this type is fairly uncommon.
- psoriatic arthritis – this type is fairly uncommon and is associated with the skin condition psoriasis.
- undifferentiated arthritis – this type is fairly uncommon and is where the arthritis doesn’t fit the pattern of any of the other forms of JIA.
Symptoms of juvenile arthritis
The main symptom of juvenile idiopathic arthritis is having painful joints for no obvious reason. Symptoms can include limping, stiffness, avoiding using an arm or leg due to pain, clumsiness of the hands, fevers, and swollen joints.
Different types of juvenile arthritis can have different patterns of symptoms:
- Oligoarthritis (arthritis in 1–4 joints) usually starts at preschool age. The child often has knee pain, which can be worse in the mornings.
- Polyarthritis (arthritis in 5 or more joints) often affects small joints in the hands or feet, and can also affect large joints like knees. The child may have matching pain in both hands or both feet.
- A child with systemic arthritis (Still’s disease) may have fever and skin rashes as well as joint pain.
- A child with psoriatic juvenile idiopathic arthritis may have pain in any number of joints, along with psoriasis (a scaly skin condition) and tiny holes in the fingernails (nail pitting). Sometimes a whole finger or toe is swollen.
Most forms of juvenile idiopathic arthritis are probably caused by the child’s immune system mistakenly attacking some of the body’s own cells and tissues.
How this happens is not known, and may involve several problems. If a child is already at risk due to genetics, these conditions could be set off by environmental factors in the womb or in childhood. Some scientists suspect that juvenile arthritis could be triggered by infections (viruses or bacteria), tobacco smoke, or stress, but none of these possible risk factors has been proven.
Who gets juvenile arthritis?
The first symptoms of juvenile arthritis are more common among preschoolers (age 1–3 years), and children in late primary school to early high school (9–14 years), than among other age groups.
An Australian national health survey found that about 1 in 1000 children younger than 16 has juvenile idiopathic arthritis. It is more common in girls than boys, and is rare in babies less than a year old.
Hospital stays for arthritis treatment are becoming more common among Australian children, especially for girls. The rate of children hospitalised for juvenile idiopathic arthritis doubled in recent years.
There is no specific test to tell whether a child has juvenile idiopathic arthritis. Children normally need referral to a rheumatologist – a specialist doctor who deals with musculoskeletal (joints, muscles and bones) disease and autoimmune disease. To get the right diagnosis, your child may need:
- blood tests
- a bone scan
- other tests such as electrocardiograph (ECG) – to test the heart, and bone marrow tests.
A child may need several blood tests for rheumatoid factor (RF) during the first 6 months after symptoms start. Tests are repeated to find out whether the test is still positive 3 months later.
Children with juvenile idiopathic arthritis can develop anterior uveitis, a serious eye condition that can cause blindness if not treated. The risk is highest for children with oligoarthritis. This condition can develop without symptoms, so children need regular check-ups. Australian guidelines recommend checking by an ophthalmologist (eye specialist) every 3–4 months for children with oligoarthritis, and every 6 months for children with polyarthritis.
Other conditions that can develop in children with juvenile arthritis include:
- having one leg longer than the other
- contracted (shortened) muscles
- ankylosing spondylitis (a type of arthritis of the spine) later as an adult – the risk is highest for children with enthesitis-related arthritis
- growth stunting – where a child has height that falls below the 5th percentile – the risk is highest for children with systemic arthritis (Still’s disease)
- blood clotting problems – the risk is highest for children with systemic arthritis (Still’s disease)
- anaemia – the risk is highest for children with systemic arthritis (Still’s disease).
Juvenile arthritis treatment
Aims of treatment
The main aim of treatment is to get the inflammation and pain under control as quickly as possible so that a child can continue a normal active life. This helps minimise the risk of long-term disability.
In the past, doctors focused on measuring the amount of inflammation to see whether treatment was working. Now they are more interested in whether a child can stay active and have a normal everyday life.
Medicines (drug treatments) for juvenile idiopathic arthritis
Several different types of medicines are used to manage juvenile idiopathic arthritis, including:
- nonsteroidal anti-inflammatory drugs (NSAIDs) such as naproxen (e.g. Inza, Naprosyn), indomethacin (e.g. Arthrexin, Indocid) and ibuprofen (e.g. Advil, Brufen)
- injections into the joint with cortisone-type anti-inflammatory medicines (corticosteroids) such as triamcinolone
- oral corticosteroids (cortisone-type anti-inflammatory medicines) such as prednisone (e.g. Panafcort, Predsone, Sone) or prednisolone (e.g. Panafcortelone, PredMix)
- disease-modifying antirheumatic drugs (DMARDs), such as leflunomide (e.g. Arabloc, Arava, Lunava), methotrexate (e.g. Methoblastin) prescribed only by specialists, and sulfasalazine (e.g. Pyralin, Salazopyrin), and (less common) hydroxychloroquine (e.g. Plaquenil)
- ‘biological’ DMARDS, such as etanercept (Enbrel) and adalimumab (Humira).
Many children will need more than one type of treatment, either over time or in combination.
In Australia, children with juvenile arthritis are often given NSAIDS to help with pain and stiffness, especially during the early stages of the disease. NSAID treatment is usually only short term. These medicines are available in Australia either on prescription or over the counter. Some brands are only available for some age groups, and some are not funded by the Pharmaceutical Benefits Scheme (PBS).
Corticosteroid injections into the joint are the main treatment for Australian children with oligoarthritis, and are also sometimes used for polyarthritis. Injections can be effective for 6–12 months. Injections are generally done under general anaesthetic for younger children and those who need treatment for more than one joint, and under sedation or with strong painkillers for older children.
Oral corticosteroids (prednisone or prednisolone) are used for children with polyarthritis who have severe pain and stiffness even while taking NSAIDs. These medicines are only used for a short while. Children taking these medicines need to be checked often so that the dose can be adjusted and, if possible, gradually reduced.
DMARDs are specialised arthritis medicines used for children with more severe arthritis. Australian guidelines recommend that DMARD treatment for children with polyarthritis begins early after diagnosis. Treatment with biological DMARDS is subsidised by the Pharmaceutical Benefits Scheme for children with severe juvenile idiopathic arthritis. In Australia, the newer ‘biological’ DMARDS, etanercept (Enbrel) or adalimumab (Humira), are being used more and more for children with arthritis.
For children with systemic arthritis (Still’s disease), treatment can include corticosteroids such as methylprednisolone given by intravenous infusion (drip). Occasionally, children with severe symptoms are given other medicines that are normally used for adults with rheumatoid arthritis.
As well as treatment by their general practitioner and rheumatologist, children with arthritis in several joints may need treatment from several allied health professionals such as physiotherapists, occupational therapists, orthotists and dietitians. Some children and their families may also need help from a social worker or nurse educator.
Some children with oligoarthritis may need casts or splints, often with physiotherapy to improve flexibility strengthen their muscles. Orthotics and shoe inserts can be effective to reduce foot pain and improve activity.
Exercise may help some children and is generally not harmful, but it is not proven to improve the symptoms of juvenile idiopathic arthritis.
Psychological treatment, such as relaxation and cognitive behavioural therapy, might help children and adolescents cope with long-term pain. Psychological treatment programs via the internet might help children and adolescents control their pain.
Outlook and recovery
Many children with juvenile idiopathic arthritis no longer have symptoms by the time they reach adulthood. Children who test positive for rheumatoid factor are more likely to have arthritis as adults.