Adult-onset Still's disease

Adult-onset Still's disease (AOSD) is a form of Still's disease, a rare systemic autoinflammatory disease characterized by the classic triad of fevers, joint pain, and a distinctive salmon-colored bumpy rash. The disease is considered a diagnosis of exclusion. Levels of the iron-binding protein ferritin may be extremely elevated with this disorder. AOSD may present in a similar manner to other inflammatory diseases and to autoimmune diseases, which must be ruled out before making the diagnosis.

Prognosis is usually favorable but manifestations of the disease affecting the lungs, heart, or kidneys may occasionally cause severe life-threatening complications. It is treated first with corticosteroids such as prednisone. Medications that block the action of interleukin-1, such as anakinra, can be effective treatments when standard steroid treatments are insufficient.

Obvious similarities exist with juvenile rheumatoid arthritis (also known as "juvenile-onset Still's disease"), and there is some evidence that the two conditions are closely related.