Around 50, 000 adolescents and children in Germany suffer from juvenile idiopathic arthritis. Every year, 1, 000 children in Germany become ill. "Idiopathic" means that the cause of the illness is unknown, and "juvenile" means that the onset of the disorder is before the age of 16. It is a particularly aggressive form of rheumatoid arthritis.
Course of juvenile idiopathic arthritis
The chronic disease affects joints, tendons and bursae, but also internal organs, nervous system and eyes. Their course is similar to that of rheumatoid arthritis in adults, but the destruction process of the joints starts much earlier. A particularly dreaded complication of juvenile idiopathic arthritis is AA amyloidosis, diseased protein deposition almost throughout the body. This can result in significant disturbance of organ function and lead to kidney failure. A special danger exists for the eyes of the children. In about ten percent of children with diseased skin develops a rheumatic inflammation of the iris, which can lead to eye damage to blindness.
Triggers juvenile idiopathic arthritis
Why young people suffer from juvenile idiopathic arthritis, the medicine could not clarify clearly until today. Presumably, an inherited predisposition in connection with external factors leads to a so-called autoimmune reaction: The immune system confuses the body's own tissue with infectious agents (bacteria or viruses) and starts an inflammatory reaction. New research has shown that the cytokine tumor necrosis factor alpha (TNFa) triggers and amplifies chronic inflammation. Cytokines are messengers that control the body's defense in the immune system.
Most commonly, juvenile idiopathic arthritis affects the small joints on the hands and feet, often the elbows, shoulders, hips, knee and ankle joints. Typical signs are painful swelling, effusions, pressure sensitivity and restricted mobility. Tendon sheath and bursitis as well as conspicuous thickening under the skin on the extensor side of joints, known as rheumatoid nodules, indicate an infection of the soft tissues in the locomotor system.
When internal organs and organ systems are affected, the body often reacts with a high fever accompanied by rashes. Dry mucous membranes of the mouth and eyes, ocular inflammation of the conjunctiva and cornea, enlargement of the spleen and liver, or lymph node swelling are other typical symptoms.
Rheumatic pains occur especially at rest. Often they are strongest at night, have a pronounced morning stiffness, and improve with exercise. The child often tries to reduce joint pain by holding the joint in a resting position midway between flexion and extension. Loss of appetite. Weight loss, fatigue, listlessness and depression affect those affected additionally.