Adult-onset Still disease

**Definition:** Adult onset Still's disease is a rare rheumatic condition characterised by a combination of symptoms, such as fever higher than 39 degrees C, cutaneous rash during fever peaks, joint or muscle pain, lymph node hypertrophy, increase of white blood cells (especially polymorphonuclear neutrophils) and abnormalities of liver metabolism.

**Long definition:** Adult onset Still disease (AOSD) is a rare rheumatic condition that present with the combination of symptoms, such as fever higher than 39°C lasting weeks, arthralgia, nonpruritic salmon colored cutaneous rash (usually over trunk) during fever peaks, pharyngitis, lymphadenopathy, splenomegaly, increase of white blood cells (especially polymorphonuclear neutrophils), and abnormalities of liver function tests. Antinuclear antibody and rheumatoid factor are negative. Markedly elevated concentrations of serum ferritin that correlate with disease activity are common. Because several other diseases, notably infectious diseases, neoplastic diseases, or other rheumatic disorders may produce similar symptoms, the diagnosis is retained when the other possible diagnoses have been completely ruled out. (J Rheumatol 1992;19:424-430

**Exclusions:** - Still disease NOS