<prompt> Amongst various current criteria for FUO Fever of Unknown origin, one relates to body temperature98.4deg F99.4deg F100deg F101deg F  <response>: Ans. d 101deg F. Ref: Harrisons 17th edition, P. 130.PUOFUO Petersdorf and Beeson 1961 Temperature 101deg F 38.3degF on several occasions Duration of fever 3 weeks Failure to reach diagnosis despite inpatient investigations for 1 week.Also Remember:Neutropenic FUO Neutrophil count 500cmmHIV Associated FUO Duration of fever 4 weeks And inpatient investigation with failure to reach diagnosis is 3 daysMost common cause of PUO Infection 26 -mc extrapulmonary TBMost common cause of PUO in elderly Multisystem disease Giant cell artheritisUndiagnosed Cause for FUO 25-30Malignancies associated with FUO Ca colon most common cause Hepatoma Gall bladder Ca Lymphoma, leukemia Pancreatic cancer Renal cell cancer Sarcoma Atrial myxoma Renal angiomyoliposa 