M08.2: Juvenile arthritis with systemic onset

Juvenile arthritis with systemic onset, also known as systemic juvenile idiopathic arthritis, is a type of arthritis that affects children. It is characterized by joint inflammation that can cause pain, swelling, and stiffness, often affecting the knees, ankles, and wrists. The unique aspect of this condition is that it just doesn't restrict itself to joints; it also presents itself with systemic symptoms like a prolonged high fever that can last for a couple of weeks or more, a skin rash that appears and disappears with the fever, and inflammation of internal organs such as the heart and lungs. The exact cause remains unknown but it's believed to be an autoimmune disorder, which means the body's immune system attacks its own cells and tissues. The disease progression varies greatly between individuals, some experience mild symptoms while others may have a more severe progression that can reduce mobility.