Rheumatoid arthritis and juvenile arthritis are both types of inflammatory arthritis; however, learn their differences below.
Although juvenile arthritis (JA) and rheumatoid arthritis (RA) are types of inflammatory arthritis, these conditions are distinct.
Some differences include:
- JA affects children younger than 16 years, where one or more joints get affected for at least six weeks. However, RA mainly affects adults.
- RA that mainly affects adults is usually chronic and lasts for a lifetime, whereas children usually outgrow JA.
- Bone development and overall growth in children may be hampered due to JA, whereas RA does not affect growth and development.
- JA has many subtypes, whereas RA is homogenous and doesn’t have subtypes.
- Children with JA have better survival rates than adults with RA.
What is rheumatoid arthritis?
Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by pain and inflammation in more than one joint (polyarthritis) of the hands and feet.
- It’s an autoimmune disease, in which the immune system of the body attacks healthy cells, resulting in inflammation of the membrane lining the joints (synovial membrane) and damage to joint tissue.
- RA affects other organs such as the skin, heart, lungs, and eyes, resulting in side effects.
The annual incidence of RA is approximately 3 cases per 10,000 people worldwide.
What is juvenile arthritis?
Juvenile arthritis (JA) mainly affects children and causes joint swelling and stiffness.
There are several types of JA, which include:
- Oligoarticular JA:
- There are two types of oligoarticular JA based on whether more joints are affected after six months:
- Persistent: Affects one to four joints in the first six months without further progression of disease after six months
- Extended: More joints get affected after a six-month gap
- There are two types of oligoarticular JA based on whether more joints are affected after six months:
- Systemic onset JA: This type of JA affects one or more joints and is often accompanied by high fever and skin rash. It is the least common type of JA, affecting 1 in 10 to 1 in 7 children. Systemic onset JA can lead to inflammation of internal organs such as the heart, liver, spleen, and lymph nodes.
- Polyarticular JA: It may affect five or more joints in the first six months of disease. A blood test performed to determine the rheumatoid factor (RF) can reveal the presence of RF.
- Psoriatic arthritis: It is a combination of psoriasis and arthritis. Psoriasis may be characterized by red, scaly skin in some children. In others, children may have arthritis and two or more of the following:
- Inflammation of a finger or toe
- Pits or ridges in fingernails
- A first-degree relative with psoriasis
- Enthesitis-related JA: This type of JA is a combination of arthritis and enthesitis. Enthesitis is tissue swelling at the area, where the bone meets a tendon or ligament. The most affected sites are the hips, knees, and feet.
- Undifferentiated arthritis: This type of JA does not fit into any of the above categories and is characterized by two or more symptoms that may or may not match the symptoms of other JA.
Does juvenile arthritis lead to rheumatoid arthritis?
Most adults with rheumatoid arthritis (RA) test positive for the presence of rheumatoid factor (RF), whereas some test negative.
Usually, children with juvenile arthritis (JA) outgrow their disease. However, some kids with positive RF will develop arthritis during their adulthood. Children with positive RF have the second most common type of JA—polyarticular JA. Polyarticular JA is closely related to adult RA.
A blood test to confirm the presence of RF is necessary to identify if the child has an early-onset adult RA. However, an early-onset adult RA occurs rarely in about five percent of all JA diagnoses.