Pauciarticular juvenile rheumatoid arthritis (PJRA) is a form of arthritis that affects children and adolescents. The pauciarticular in PJRA means that it involves fewer than five joints.

PJRA is a previous term used for this condition, which is now known as oligoarticular juvenile idiopathic arthritis (oligoarticular JIA). It is one of several subtypes of JIA.

The term juvenile rheumatoid arthritis is no longer widely used by healthcare professionals. This is because most forms of juvenile arthritis are different from adult rheumatoid arthritis. Oligoarticular JIA is also known as oligoarthritis.

Oligoarticular JIA causes the child’s immune system to attack the tissue lining of their joints, called the synovium. This causes inflammation, making the joint tender, painful, or hard to move.

Read on to learn more about oligoarticular JIA, including its symptoms, causes, and treatments.

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The word oligoarticular means “few joints”. A child with oligoarticular JIA will have up to four joints affected. The American Academy of Orthopaedic Surgeons (AAOS) notes that around 50% of children with juvenile idiopathic arthritis (JIA) have the oligoarticular form.

Oligoarticular JIA mainly affects a child’s lower limbs, such as the knee or ankle. Common symptoms of JIA include:

  • joint pain and stiffness, which may increase after waking up or being in the same position for too long
  • red, tender, warm, or swollen joints
  • fatigue
  • rash
  • appetite loss
  • fever
  • blurred vision
  • dry, gritty eyes

The AAOS states that approximately half of children with oligoarticular JIA experience symptoms in only one joint. Experts call this form of JIA monoarticular juvenile arthritis. A child with monoarticular juvenile arthritis may have mild symptoms that reduce or disappear altogether.

Oligoarticular JIA can also affect a child’s eyes. Around 20–30% of children with oligoarticular JIA also develop eye inflammation, called uveitis. This affects the inner layer of the eye, causing blurry vision and eye pain.

If a child with oligoarticular JIA experiences vision problems, they may require regular checkups with an ophthalmologist, a doctor specializing in eye care. If a child is antinuclear antibody (ANA) positive, they are evaluated every several months. Without regular checkups, a child with uveitis may develop a permanent visual impairment or even go blind.

Oligoarticular JIA occurs when a child’s immune system attacks the synovium of their joints. However, experts currently do not know the exact cause of oligoarticular JIA.

Specialists suggest that some children may have genes that cause oligoarticular JIA to develop in the presence of a virus, bacteria, or other external factor. Female children under the age of 8 years old are also more likely to develop oligoarticular JIA.

Oligoarticular JIA is not an inherited disease — a child’s parents cannot pass it on to them.

There are two types of oligoarticular JIA that a child can develop::

Persistent oligoarticular JIA: This term is used when oligoarticular JIA continues to only affect four or fewer joints.

Extended oligoarticular JIA: This may develop six months after oligoarticular JIA symptoms begin. A child with extended oligoarticular JIA will begin to feel oligoarticular JIA symptoms in more than four joints. Extended oligoarticular JIA occurs in one-third of children who have oligoarticular JIA.

A child has to meet certain characteristics to receive a JIA diagnosis. They have to be under the age of 16 and have experienced inflammation for more than six weeks. Additionally, doctors must rule out other causes of pain.

A doctor may then refer the child to a pediatric or adult rheumatologist, a doctor specializing in arthritis treatment. The doctor may ask about the child’s medical history, when symptoms started, and how long they lasted.

The child’s doctor may also examine them for any joint pain, warmth, or tenderness. They may also test the child’s range of motion and look for any signs of stiffness. Additionally, the doctor may check the child’s eyes for signs of inflammation.

The doctor may also need to take a sample of the child’s blood to look for any indicators of arthritis. Blood tests for JIA can include:

Erythrocyte sedimentation rate (ESR) test: This measures the rate that red blood cells settle at the bottom of a test tube. A high ESR rate indicates active inflammation.

C-reactive protein (CRP) test: CRP is a protein found in a person’s blood. CRP levels increase when there is inflammation in the body.

Antinuclear antibody (ANA) test: This looks for the presence of ANAs within a person’s blood. ANAs may indicate that a person has an autoimmune disorder, but this can be detected in other conditions.

A doctor may also order tests, such as X-rays or ultrasounds, to look for any indicators of joint damage and inflammation.

There is currently no cure for oligoarticular JIA. However, a child may be able to have reduced or no symptoms with proper treatment. Treatment for JIA includes:

Medication

There are various medications for the treatment of oligoarticular JIA. These can include:

  • disease-modifying antirheumatic drugs (DMARDs), which suppress the immune system to prevent it from attacking a child’s joints
  • nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, to help relieve inflammation and pain
  • biologic agents that work to slow the progression of JIA, although these are generally only used if DMARDs do not work
  • corticosteroids, which is a stronger form of medication that doctors may use to treat more severe JIA

Surgery

If a child has a very severe form of oligoarticular JIA or is experiencing serious complications, they may require surgery.

Surgery for oligoarticular JIA can involve repositioning joints or removing loose pieces of cartilage.

A surgeon may also need to replace parts of a damaged joint with a metal, plastic, or ceramic prosthesis.

Non-medical treatment

Non-medical treatments, such as exercise and physical therapy, may benefit a child with oligoarticular JIA. Low-impact activities, such as walking or yoga, may help to relieve joint stiffness or pain. Additionally, physical therapy can help a child with oligoarticular JIA improve their balance and coordination.

Occupational therapy may also be useful to a child with oligoarticular JIA, as it can help them learn about staying active and performing daily tasks easily.

Additionally, there are certain habits and lifestyle changes that can help ease oligoarticular JIA pain, such as:

  • cutting back on fatty, sugary, and processed foods
  • eating fish, fruit, vegetables, whole grains, and extra virgin olive oil
  • using heat pads and taking warm baths when joints become stiff
  • using ice packs on areas of pain and inflammation
  • trying relaxation techniques, such as meditation or reading
  • having massage or acupuncture
  • taking breaks to rest

PJRA is an older term used to describe oligoarticular juvenile idiopathic arthritis (oligoarticular JIA). Oligoarticular JIA is a form of arthritis that affects children and is one of several subtypes of JIA. Oligoarticular JIA causes inflammation in up to four joints in a child’s body, causing stiffness and pain.

Oligoarticular JIA can also cause eye inflammation, called uveitis. It is important that a child with oligoarticular JIA who develops uveitis has frequent eye checks to prevent blindness.

To receive a diagnosis of oligoarticular JIA, a child needs to be under the age of 16 and experience inflammation for more than six weeks. A doctor may ask questions about the child’s medical history and pain when diagnosing oligoarticular JIA. A doctor may also order blood or imaging tests to look for signs of oligoarticular JIA.

There is currently no known cause of oligoarticular JIA. However, experts suggest that oligoarticular JIA may result from genes reacting to certain outside factors, such as a virus.

There is currently no cure for oligoarticular JIA. However, treatments for oligoarticular JIA can help to reduce symptoms. Caregivers should speak with a doctor about what oligoarticular JIA treatment would work best for their child.