owever, as paediatric rheumatologists, we regularly treat younger patients — from toddlers to teenagers — with arthritis.

Arthritis can be transient, but when it lasts for at least six weeks, then it moves into the realm of chronic arthritis. Once other secondary causes have been ruled out in such a patient, by a thorough history, physical, and directed investigations, then the diagnosis of Juvenile Idiopathic Arthritis (JIA) can be made.  JIA affects about 1 in 1,000 Canadian children. It causes stiffness, pain, and swelling of the joints. If not treated promptly and effectively, it can lead to permanent joint damage, disability, and chronic pain.

Every child with JIA needs regular screening eye exams because this type of uveitis can be asymptomatic.  Untreated, uveitis can lead to cataracts, glaucoma (increased eye pressures), or even blindness.

Children can be diagnosed with one of seven different subtypes of JIA. Depending on the subtype, different joints can be involved and different extra-articular (non-joint) manifestations of disease can occur, requiring different treatments. One of the subtypes is called oligoarticular JIA. This is the most common form of the disease and involves four or less joints within the first six months of disease. It typically starts at a very young age (peak incidence is between one and two years of age) and affects three times as many girls as boys.  Common joints to be affected in these children are the knees and ankles. Parents may notice that their child is stiff in the mornings, often limping or asking to be carried.  The stiffness may then improve throughout the day.  If a child has a fever, rash, or other systemic symptoms along with the arthritis, then they may have systemic arthritis, another subtype of JIA. This condition, previously known as Still’s disease, affects boys and girls equally. These children can be very unwell and need urgent assessment and treatment. A third subtype of JIA is called polyarticular rheumatoid factor (RF) positive JIA. This subtype involves five or more joints in the first six months of disease and resembles the adult disease rheumatoid arthritis.  Although this subtype can occur at any age under 16 years, the most common peaks include one to three years and later childhood/adolescence.

An important complication of JIA to be aware of inflammation of the eyes, called uveitis.  Every child with JIA needs regular screening eye exams because this type of uveitis can be asymptomatic.  Untreated, uveitis can lead to cataracts, glaucoma (increased eye pressures), or even blindness.

Hope for the future

The good news is that research has come a long way in the field of paediatric rheumatology in recent years and the treatments available for JIA are now quite good.  Our goal is for all patients with JIA to have zero inflammation and to live active, productive lives.  Exercise is good for arthritis and physiotherapy is often part of the treatment plan.

As a parent, if you suspect that your child has a form of JIA, then you should make an appointment for them to see their family physician or paediatrician (or, alternately, if they are unwell, bring them to the emergency department).  Prompt referral to a paediatric rheumatologist for assessment should then be made at the discretion of the treating physician.