Not only acute rheumatic fever (rheumatic heart disease) but chronic arthritis is also very dangerous for children as it can cause severe joint damage, leading to disability. This disease is commonly seen in individuals under the age of 16.
Currently, the mechanism of chronic arthritis in adolescents is still not well understood. There is a recorded presence of certain immune antibodies depending on the disease form: HLA B27 is found in 90% of cases of juvenile spondyloarthritis, anti-nuclear antibodies (ANA) in oligoarticular forms, and rheumatoid factor (RF) in polyarticular forms. For systemic disease or polyarthritis, the mortality rate after 15 years can reach 10-15%.
When a child under 16 years old presents with swelling and pain in at least one joint lasting more than 6 weeks, chronic juvenile arthritis should be considered as a potential diagnosis. Clinically, three pathological forms may be encountered:
Systemic Form (also known as Still’s Disease)
Children often experience fluctuating fever, fatigue, and generalized muscle pain; these symptoms do not improve with standard doses of aspirin. Children may develop rashes on the trunk and extremities (90%), but these rashes disappear quickly. Joint inflammation may occur from the outset or after a few days, typically affecting the wrists, knees, and ankles bilaterally. Other symptoms may include lymphadenopathy, hepatosplenomegaly, and multi-organ inflammation such as pleural effusion, pericarditis, or glomerulonephritis.
Polyarticular Form
This form of the disease has a gradual onset; there are three subtypes:
With Rheumatoid Factor (1 in 4 cases): This can be considered as juvenile rheumatoid arthritis. It presents with symmetrical joint inflammation, causing joint destruction and specific damage to both hands and feet, but may also affect all other peripheral joints. If the temporomandibular joint is severely affected, the child’s nutritional status may be significantly impacted.
With Anti-Nuclear Antibodies (ANA): This is commonly seen in children under 5 years old. Symptoms of polyarthritis may occur early or as secondary diffuse oligoarthritis.
No Immune Markers: In this form, the swollen joints are not significantly enlarged but become stiff very quickly.
Oligoarticular Form
Early Onset Type: Occurs in 90% of cases in girls. 1-4 joints are asymmetrically affected, most commonly the knee, ankle, and wrist joints. The disease can cause complications such as cataracts, increased intraocular pressure, and conjunctival damage that may lead to blindness.
Late Onset Type: Often seen in cases of juvenile spondyloarthritis, 85% occur in boys aged 10-12. Asymmetrical peripheral arthritis is commonly observed in the upper limbs.
Clinically, if joint swelling is difficult to determine, ultrasound can be used for diagnosis. If there is effusion, aspiration is necessary to test the joint fluid in cases of suspected joint infection. X-rays usually do not provide significant value in the early stages as changes such as joint space narrowing, bone erosion, or joint cavity defects are not yet visible. Magnetic Resonance Imaging (MRI) may be indicated for cases of difficult-to-assess joint effusion, such as in the hip joint.
In terms of immunological testing, the presence of rheumatoid factor and anti-nuclear antibodies is sufficient to confirm the disease type after clinical examination.
However, it is also essential to exclude other conditions that may present similarly, such as acute rheumatic fever, joint infections, tumors, or joint damage from hematological disorders.
Chronic arthritis in children is treated with analgesics, anti-inflammatory medications, corticosteroids, and physical therapy. All treatments must be guided and closely monitored by a physician.
