Juvenile idiopathic arthritis (JIA): joint symptoms, eye screening and treatment

Versus Arthritis explains the name: juvenile means under 16, idiopathic means other causes have been ruled out and there is no other explanation, and arthritis means a joint swells, stiffens and becomes inflamed. It is an autoimmune condition, meaning the immune system gets confused and attacks the body's own healthy tissue, causing inflammation in the joints when it is not needed. It is different from the rheumatoid arthritis usually diagnosed in adults.

The cause is not completely understood. Versus Arthritis says it is thought to be a combination of factors such as genes, and that it is not something a child or parent has done or caused. Leeds Teaching Hospitals adds that hearing the diagnosis can be a shock because people often think arthritis affects only older people.

Leeds lists features of an inflamed joint as swelling, pain, stiffness, especially in the morning, and warmth, and says tiredness is common when arthritis is active. Less commonly there can be fever, rash, loss of appetite and weight loss. Versus Arthritis lists symptoms in any joint, including fingers, wrists, elbows, knees, ankles and hips, and says JIA can also cause a high fever, skin rashes, and blurry vision or dry eyes. Children may develop arthritis in different joints from those first diagnosed.

Versus Arthritis describes the following subtypes, noting that over time a child's subtype might change.

Leeds says most, but not all, subtypes carry a significant chance of uveitis, inflammation inside the eye caused by the same autoimmune process. It does not cause symptoms in young children and a doctor cannot tell by just looking without specialised equipment. If not picked up and treated it can cause permanent vision loss, so regular checks with an ophthalmologist are very important. The procedure is painless, and if uveitis is found it is treated with special eye drops or other medicines.

Sheffield Children's says the British Society for Rheumatology and the Royal College of Ophthalmologists have jointly produced a national screening guideline, that a screening appointment is offered within 6 weeks of the initial diagnosis and regularly thereafter, and that untreated uveitis can cause cataracts, glaucoma and macular oedema. Families are asked not to skip these appointments even if the child has no eye symptoms.

Versus Arthritis says there is no one test and a child might see a few doctors before diagnosis. Doctors look for symptoms lasting 6 weeks or longer, starting before the 16th birthday, with signs of other conditions that can cause joint symptoms having been considered. Tests or scans may be used, but not everyone has the same ones, and working out the subtype is not always easy.

Leeds says treatment is tailored to each child, with goals of returning to normal activities, reducing pain, preventing joint damage and keeping joints working. The main approaches are medicines to control inflammation, steroid joint injections, exercises to keep joints moving and muscles strong, and pain management strategies. Versus Arthritis lists painkillers such as paracetamol, anti-inflammatory drugs such as ibuprofen, disease-modifying drugs such as methotrexate, steroids, and biologics and biosimilars, given as tablets or injections, and says it can take a while to find what works. It also describes physiotherapy and occupational therapy. Which medicines a child needs is decided by the paediatric rheumatology team.

Leeds says that with treatment most children have no or only minor joint problems most of the time, that modern treatments can control most JIA and avoid most long-term consequences, and that the vast majority can pursue all activities they wish apart from flares. Versus Arthritis says symptoms vary day to day, that a flare is a temporary worsening which should be reported to the healthcare team because a different treatment might be considered, and that young people with arthritis are more likely to struggle with mental health, so a supportive network and counselling can help. It also provides guidance for schools and information for parents.