Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Classical pyrexia of unknown origin (PUO), defined as fever of >38 °C on several occasions for greater than three weeks despite investigation in hospital (>3 days) or out of hospital (>2 visits), is an uncommon but challenging problem. The incidence and aetiology vary according to the geographic region, the age structure of the population, and the immune status of the patient; alternative definitions of PUO exist for immune compromised individuals. Preliminary investigations should be determined by detailed history and repeated examination. Biopsy of abnormal tissues should be performed early. If uncertainty persists, abdominal computerised tomography (CT), radiolabeled white cell scans, and the Duke endocarditis criteria carry the highest diagnostic yield. Blind bone marrow biopsy is probably only useful in immunocompromised patients.


Journal article


Acute medicine

Publication Date





10 - 14


Specialist Registrar Department of Microbiology and Infectious Diseases Brighton and Sussex University Hospital Eastern Road, Brighton Sussex, BN2 5BE United Kingdom.