Still's disease, also known as systemic juvenile idiopathic arthritis (sJIA), is a rare chronic autoimmune disease that causes inflammation in the joints, organs, and tissues. Other synonyms or terms used to describe Still's disease are juvenile idiopathic arthritis (JIA), systemic-onset JIA, idiopathic systemic arthritis, autoinflammatory syndrome associated with early-onset arthropathy (ASEA), and juvenile-onset Still's disease (JOSD). While each term has a slightly different focus or classification system, they all refer to the same condition characterized by high fevers, rash, joint pain and swelling, and systemic inflammation. Treatment usually involves a combination of medication and physical therapy to manage symptoms and prevent joint damage.