Adult onset Still’s disease (AOSD) is a rare inammatory disease characterized by fever, arthralgia, rash, sore throat, lymphadenopathy,
hepatomegaly and/or splenomegaly. It is a rare cause of pyrexia of unknown origin (PUO) and should be considered once the more common
infectious, rheumatological and malignant causes have been excluded. This is usually a diagnosis of exclusion. Yamaguchi criteria can be used for
diagnosis. Patients of AOSD show an excellent response to Non-steroidal anti-inammatory drugs (NSAIDs), however some may not have a
sustained effect, in which case glucocorticoids have to be considered. Here’s a case of a young male patient who was evaluated for the cause of
pyrexia of unknown origin.