Juvenile idiopathic arthritis (JIA) is inflammatory arthritis that starts in children under 16.
Most forms of JIA are due to an immune system malfunction. While the exact cause of this auto-immune issue is unknown, the malfunction provokes a child’s immune system to attack their joint linings, causing inflammation and joint damage.
This form of juvenile arthritis can involve one or more joints and occasionally affect the eyes.
Types of JIA
Research suggests that there may be many different types of JIA with slight differences.
The most common types of juvenile arthritis are:
- Oligoarthritis. This type typically affects four or fewer joints in the first 6 months of onset. The most often affected joints are the knees, ankles, and elbows. People with this type of juvenile arthritis are at a more significant risk of developing inflammation in the eyes.
- Polyarthritis. This typically involves more of the body than oligoarthritis. It affects five or more joints in the first 6 months of illness.
- Systemic JIA. This type can cause inflammation in one or more joints, a skin rash, and enlargement of the liver, lymph nodes, or spleen. A fever that lasts for 2 or more weeks before or after the start of the disease is also typical.
- Psoriatic JIA. This type emerges when psoriasis is present alongside additional symptoms such as nail pitting, nail separation, and the swelling of a single finger or toe.
- Enthesitis-related JIA. This variety involves a tenderness where bone meets ligaments or tendons along with arthritic inflammation. The most common areas impacted are the hips, knees, and feet.
Common Signs of JIA
The signs of arthritis can come and go in flare-ups. During an outbreak, symptoms worsen. Symptoms go into remission between flare-ups.
JIA manifests differently in everyone. A child may have a few flare-ups and then never have symptoms again. They may also encounter regular flare-ups or flare-ups that never go away.
While certain types of juvenile arthritis have distinct symptoms, some commonplace symptoms can show up throughout all types.
Joint pain and loss of mobility
The most common symptom of JIA is joint pain. Joints may swell and grow tender. They can turn red and feel warm to the touch. Joints may become stiff and lose their mobility. This can result in a loss of dexterity in the hands.
If JIA is left untreated, children may become less physically active due to pain and loss of mobility. If JIA persists for an extended time