Overview of Juvenile Idiopathic Arthritis (JIA)
Like adults, children can develop arthritis, a condition that causes inflammation of the joints. The most common type of chronic, or long-lasting, arthritis that affects children iscalled juvenile idiopathic arthritis (JIA). JIA is a broad term that includes several differentdiseases. Symptoms can vary depending upon the type of JIA and can includejoint pain, swelling, warmth, stiffness, and loss of motion. JIA may last a limited time, such as a few months or years, but in some cases it is a lifelong disease that requires treatment into adulthood.
JIA is “idiopathic,” meaning that its origins are not understood. While the exact causes of JIA are unknown, it begins when the immune system becomes overactive and creates inflammation.
Withtreatment,mostchildrenachieveperiodswherethey do not have symptoms and the disease is not active(remission), and sometimes the disease goes away permanently with no further need for medications. It is important to see a doctor early if your child has swollen or stiff joints because delaying therapy can lead to joint damage, a lesser response to treatment, and other problems.
Who Gets Juvenile Idiopathic Arthritis (JIA)?
JIA begins in children and adolescents before the 16th birthday. Most formsof JIA are more frequent in girls, but enthesitis-related JIA (described below)is morecommoninboys. Systemic JIA (described below) affects boys and girls equally. Children of all races and ethnic backgrounds can get JIA.
It is very rare for more than one member of a family to have JIA, but children with a family member with chronic inflammatory arthritis, including JIA, are at a slightly increased risk of developing it. Some children with JIA have family members with other autoimmune conditions likepsoriasis, inflammatory bowel disease,autoimmune thyroid disease, celiac disease, typeI diabetes, and other disorders.
Symptoms ofJuvenile Idiopathic Arthritis (JIA)
Symptoms of JIA vary depending on the type, but all forms share persistent joint pain, swelling, warmth, and stiffness that are typically worse in the morning and after a nap or prolonged sitting. The pain may limit movement of the affected joint, although many children, especially younger ones, will not complain of pain. One of the earliest signs may be limping in the morning due to disease in one or both legs.
The symptoms of JIA may go through cycles, flaring for a few weeks or months followed by periods when they go into remission. Some children have just one or two flares and never have symptoms again, while others have many flares or symptoms that never fully go away.
Besides joint problems, the inflammation associated with JIA can cause other symptoms, such as:
- Eye inflammation. Uveitis (inflammation of the front and middle parts of the eye) often occurs in children with JIA. It usually starts within a few years after the JIA diagnosis, but in a small percentage of children, it appears before the joint symptoms or many years afterward. The type of JIA a child has may cause the development of different types of uveitis. Children with:
- Oligoarticular JIA, especially when it begins at an early age, can have chronic (long-lasting) uveitis that has mild or no symptoms. Children with polyarticular JIA without rheumatoid factor, or with psoriatic JIA are also at risk.
- Enthesitis-related JIA and some children with psoriatic JIA can have episodes of acute anterior uveitis, which has a sudden onset and causes eye pain, eye redness, and sensitivity to light.
If left untreated, uveitis can lead to eye problems such as cataracts, glaucoma, and vision loss, so it is important for children with JIA to have frequent eye exams with an ophthalmologist.
- Skin changes. Depending on the type of JIA a child has, he or she may develop skin changes. Children with:
- Systemic JIA who have fevers can get a light red or pink rash that comes and goes.
- Psoriatic JIA can develop scaly red patches of skin. Psoriatic JIA can also cause pitted nails and dactylitis (swollen fingers or toes).
- Polyarticular JIA with rheumatoid factor can get small bumps or nodules on parts of the body that receive pressure, such as from sitting.
- Fever. Patients with systemic JIA typically have daily fevers when the disease begins or flares. The fever usually appears in the evening, and the rash may move from one part of the body to another, usually happening with the fever. Patients with other types of JIA do not generally develop fevers.
- Growth problems. Inflammation in children with any type of JIA can lead to growth problems. Depending on the severity of the disease and the joints involved, bones near inflamed joints may grow too quickly or too slowly. This can cause one leg or arm to be longer than the other, or can result in a small or misshapen chin. Overall growth also may be slowed if the disease is severe. Growth normally improves when inflammation is well-controlled through treatment.
