Arthritis in children: symptoms, diagnosis and treatment options

Around one in every 1,000 children in the UK has juvenile idiopathic arthritis (JIA). This type of arthritis first occurs in those aged under 16. JIA is an umbrella term used to describe different types of autoimmune arthritis and results in joint inflammation. Depending on the subtype and severity of JIA, it may affect other parts of the body too.

Here we’ll look at the different types of JIA and risk factors for the condition, as well as its symptoms, treatments and outcomes. 

Causes of JIA

As with conditions such as rheumatoid arthritis in adults, JIA is an autoimmune condition. This means your immune system mistakenly attacks healthy cells causing inflammation in your body. 

It isn’t yet clear what causes JIA — this is why it is referred to as idiopathic, which means unknown. However, genetics and environmental triggers likely have a role to play in disrupting the normal functioning of the immune system in JIA. 

Types of JIA

There are several different types of JIA that are categorised according to how they present. 

Oligo-articular JIA

Oligo-articular JIA affects one to four joints in the first six months of the disease, usually the knees, wrists and ankles, and can sometimes cause vision problems. It is the most common type of JIA and is less likely to cause permanent joint damage. 

If more joints are affected after six months, it’s called extended oligo-articular JIA and is more likely to cause permanent joint damage. Treatment may include medication such as methotrexate.

Polyarticular JIA

Polyarticular JIA is similar to oligo-articular JIA, but it affects five or more joints in the first six months of the disease. It is the second most common type of JIA. You may feel unwell and tired and symptoms can either go into permanent remission or continue into adult life. It is similar to the adult form of arthritis called rheumatoid arthritis.  

Enthesitis-related JIA

Enthesitis-related JIA causes inflammation of the joints as well as inflammation of the tissue at the sites where tendons, ligaments or other tissues attach to the bones — these sites are called entheses. 

A child with enthesitis-related JIA, therefore, has both arthritis and enthesitis. The feet, hips, spine and knees are often affected. It can be associated with a painful red eye condition called uveitis. This form of JIA can be associated with a genetic marker called HLA-B27 and there may be family members who have ankylosing spondylitis or inflammatory bowel disease (Crohn’s disease or ulcerative colitis).

Psoriatic JIA

Psoriatic JIA causes arthritis and a skin condition called psoriasis, which causes the skin to become red or silvery grey, itchy, scaly and flaky. It can also affect your nails and eyes. This form of JIA can also be associated with the HLA-B27 genetic marker and family members may also have a history of psoriasis. About a third of children with psoriatic JIA can continue to experience the disease into adulthood.

Systemic-onset JIA

Systemic-onset JIA is the least common type of JIA. It causes arthritis alongside other general symptoms, such as a fever, skin rash and inflammation of organs such as the heart, liver and spleen, as well as inflammation of the lymph nodes. This subtype of JIA can mimic other conditions and many tests may be needed before a final diagnosis is made.

Symptoms of JIA

Symptoms of JIA to look out for include painful, swollen or stiff joint(s). Joint(s) may feel warm to touch or appear red.  

Sometimes there may be a limp but no injury. Other symptoms may include feeling persistently tired, having a recurrent fever without signs of infection, or painful or blurred vision.

Getting a diagnosis of JIA

There is no single test to diagnose JIA. To make a diagnosis of JIA, a rheumatologist (a doctor that specialises in treating chronic inflammatory autoimmune conditions) will take a detailed medical history, perform an examination and may also arrange additional tests such as blood tests and imaging tests, such as an X-ray, ultrasound scan or MRI scan. 

In some cases, more invasive testing may be needed to come to a diagnosis, namely removing fluid from a joint using a needle (joint aspiration) to rule out infection, or a bone marrow examination to rule out some rare conditions that mimic systemic-onset JIA.

Treating JIA

The aim of treatment for JIA is to: 

• Control your symptoms of arthritis (joint pain, swelling and stiffness)
• Enable you to lead an active life in daily activities
• Improve your joint function and mobility
• Reduce joint damage and disability
• Help you become an independent adult

While there is no known cure for JIA, all of the above can be achieved by a combination of medical treatment, physiotherapy, occupational therapy and lifestyle changes.

Medical treatments

Painkillers, such as paracetamol and codeine, can be taken regularly to control joint pain, while non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, can be taken to help reduce joint pain, stiffness and swelling. 

To reduce the risk of joint damage and inflammation, your doctor may prescribe disease-modifying anti-rheumatic drugs (DMARDs), such as methotrexate. DMARDs can take a couple of months to take full effect. 

If DMARDs aren’t effective, your doctor may prescribe a biologic, such as etanercept, infliximab or adalimumab. Biologics are stronger medications and also work to reduce inflammation and joint damage.  Biologics can take some weeks to months to take full effect.

Steroid injections can be administered directly into affected joints to reduce inflammation and reduce the risk of long-term damage. Steroids often work within a few days and effects can be long lasting.

If your eyes are affected, medicated eye drops can be prescribed to reduce eye inflammation and reduce the pressure in your eyes.  

Other treatments 

Other supportive treatments to ease symptoms include physiotherapy, occupational therapy, massage, and wearing splints and insoles.  

Following a healthy diet, staying active, sleeping well and keeping your vaccines up-to-date will also help keep your body healthy, which is thought to help keep autoimmunity under control and improve your overall wellbeing.

Complications of JIA

JIA affects each person differently. Periods of the arthritis being highly active called flares can commonly occur after periods of infection, stress or change in medication. Flares can also occur for no apparent reason.

Flares can make the affected joints more painful, swollen and stiff and, consequently, cause reduced mobility in those joints. Overall, you may feel like you have lower energy levels and/or a reduced appetite. 

JIA can also affect your sleep and you may feel low in mood or frustrated that you cannot do everything you want to do because of your condition or due to the side effects of medication. It is important to discuss how you feel with your healthcare team so they can help you with these difficulties.

Sometimes JIA or treatment for JIA can affect growth or puberty. It can also make it difficult to brush your teeth either due to jaw pain or difficulty holding the toothbrush. Looking after your teeth with twice-daily brushing and regularly visiting a dentist is very important.  

Speak with your healthcare team if you have any concerns so they can help and guide you.

Can children grow out of JIA?

JIA, as with all autoimmune diseases, affects each individual differently.  

There are likely to be periods of high disease activity (flares) and periods when the disease is inactive and well controlled (in remission). 

It is possible for some children to experience prolonged periods of remission after adolescence, which may be spontaneous or may be treatment-induced remission. The tendency towards autoimmunity, however, is likely to remain, and regular monitoring and follow-up for JIA is advised.

Outcomes of living with JIA

JIA is a chronic health condition that can have a significant impact on your health, but with appropriate treatment, it does not affect life expectancy.  

If left untreated, joint inflammation caused by JIA can lead to permanent damage and disability in later life.  

Certain complications such as eye inflammation, cardiovascular disease and steroid side effects on bone health can affect long-term health. The impact of living with a chronic illness can also affect the emotional and social development of those with JIA.

Overall, JIA can pose challenges, but with early diagnosis and a holistic approach to care, most individuals with JIA can lead fulfilling, active lives.