Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disease characterized by the classic triad of persistent high spiking 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 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 kidney may occasionally cause severe life-threatening complications. It is treated first with steroids such as prednisone. Drugs that block the action of interleukin-1, particularly IL-1β, are effective treatments.