Juvenile rheumatoid arthritis is the type of arthritis seen in children below 17 years of age. It is also known as juvenile idiopathic arthritis, because the cause of this disease was not known earlier. It is characterised by severe inflammation, accompanied by stiffness, swelling and pain in the joints.
The common possible causes of juvenile rheumatoid arthritis, as suggested by experts are:
- Autoimmune reaction: autoimmune reaction is the term given to the pathophysiology in which body’s immune cells start destructing the body’s own cells. The immune cells are present in the body to fight the foreign cells which can cause infections in the body. These cells have amino acid sequences, known as antibodies, which identify the foreign cells as antigens. But sometimes, for unknown reasons, they start identifying the body’s own cells as foreign cells, and start acting against them, by destructing them. The process is accompanied by inflammation, which shows its characteristic signs of redness, swelling, pain and localised increase of temperature.
- A viral or bacterial infection in the joints, due to which an immune response is triggered which causes destruction of the body’s own cells along with the foreign cells.
- Children exposed to certain antibiotics during childhood are at a greater risk of developing juvenile rheumatoid arthritis later in adolescence. Various studies have shown correlations between certain antibiotics and certain type of juvenile rheumatoid arthritis.
- This disease is known to have genetic predisposition in children who have rheumatoid arthritis or any other autoimmune disease in their family.
- Women are more likely to develop rheumatoid arthritis at any age, than men.
- Juvenile rheumatoid arthritis is classified into three types:
- Oligoarticular rheumatoid arthritis: this type affects 4 or less than 4 joints in the first six months of illness. This type accounts for about 50% of the cases of juvenile rheumatoid arthritis. It usually involves the ankles, elbows and knees. The smaller joints may also be affected. It is usually asymmetrical, which can lead to growth discrepancies and asymmetrical growth.
- Polyarticular rheumatoid arthritis: this type affects 5 or more than 5 joints in the first six months of the disease.
- Systemic rheumatoid arthritis: in this type, arthritis, fever and appearance of pink rashes are seen. This group has about 10-20% of all juvenile rheumatoid arthritis cases. Both males and females are equally affected by this type. Some systemic involvement can also be seen like lymphadenopathy, hepatitis and hepatosplenomegaly.