Juvenile Rheumatoid Arthritis
What is juvenile rheumatoid arthritis?
Juvenile rheumatoid arthritis (JRA) – also known as juvenile idiopathic arthritis (JIA) – is an inflammation of one or more joints, with an onset of 16 years or younger in children or adolescents. To be classified as JRA, the condition must persist for a minimum of six weeks and all other possible causes must be excluded.
Although the exact causes of JRA remain unclear, it is known that the condition is an autoimmune disorder. This means that disordered functioning of the body’s immune system plays a role in the development of JRA.
In the majority of cases, the condition can be managed through prolonged treatment. This will typically involve a combination of medication and physical therapy.
Types of juvenile rheumatoid arthritis
There are various types of JRA, each with varying symptoms and levels of severity.
- Oligoarthritis: The most common type of JRA, affecting roughly one third of those with the condition. For diagnosis, no more than four joints in a person’s body will be affected during the first six months of developing this condition. Oligoarthritis typically affects one or both knees, and can in some cases also cause chronic eye inflammation.
- Polyarthritis: The second most common form of JRA, which can develop suddenly or steadily over a period of weeks. For diagnosis, five or more joints must be affected during the first six months of this condition developing. May cause painful inflammation of the wrists, ankles, toes, hips, knees, neck and jaw.
- Enthesitis-related JRA: This condition typically causes inflammation of the leg joints and spine, at sites where tendons or ligaments insert into joints, such as the heel. In some cases, this will be accompanied by acute uveitis (a painful eye condition). Enthesitis-related JRA is often associated with inflammatory bowel disease (IBD).
- Psoriatic arthritis: A combination of a skin rash, caused by a long-lasting autoimmune disease of the skin called psoriasis, with joint pain, usually in the fingers and toes.
- Systemic JIA:Also known as Still’s disease, this condition consists of joint pain combined with fever, tiredness, loss of weight, lack of appetite and a rash. May lead to enlarged glands in the groin, arms and neck, as well as an enlarged spleen and liver.
Juvenile rheumatoid arthritis symptoms
Some of the most common signs and symptoms of JRA include:
- Tenderness and/or swelling of the joints
- Joints that are warm to the touch
- General pain
- Stiffness (especially following sleep or inactivity)
- Sleep problems
- Swollen lymph nodes
- Weight loss and a reduced appetite
Symptoms typically vary from person to person and some are specific to certain subtypes of JRA. It is also possible for symptoms to alter over time, even over the course of a single day.
If symptoms arise it is important to seek medical attention. By examining the symptoms a child is experiencing and ruling out other possible causes, a doctor will generally be able to identify whether JRA is present.
Juvenile rheumatoid arthritis complications
With prompt and appropriate treatment, the prognosis for JRA can be greatly improved. However, without treatment or if the condition is particularly severe, complications can arise.
Complications associated with JRA can include:
- Anemia (a lack of red blood cells or hemoglobin)
- Permanent joint damage
- Disproportionate limbs
- Stunted growth (caused by the condition as well as some medications used to treat it)
- Eye inflammation (typically painful and can in very severe cases lead to blindness)
Although complications are possible, the risk of them occurring can be reduced through careful management of the condition.
Juvenile rheumatoid arthritis causes
The causes of JRA are not fully understood. However, the condition is generally thought to be linked to a dysfunction of the immune system combined with genetic and/or environmental factors.
Research suggests that JRA may be triggered by abnormal autoimmune responses to certain viruses or other agents, causing joint inflammation when it is not needed. Although it is uncommon for two members of the same family to experience JRA, genetic mechanisms are thought to play a role in determining who develops the condition.
Some research suggests human leukocyte antigens – a type of molecule which plays an important role in deciding how the body reacts to foreign agents – are particularly relevant to this process, with people with an increased frequency of a specific type of the molecule being at greater risk of developing JRA.
Arthritis Research UK. [“What causes JIA?”] (https://www.arthritisresearchuk.org/arthritis-information/young-people/juvenile-idiopathic-arthritis/causes.aspx) Accessed November 24, 2017. ↩