Fever of Unknown Origin

Abstract

A plan of management for the patient with fever of unknown origin is described. Diagnosis can be made within a week of onset of the fever in many cases, with basic observations consisting of a carefully taken and complete history, physical examination, blood cultures, urinalysis, complete blood cell count and chest x-ray. In an equally large fraction of cases the fever will disappear spontaneously without being diagnosed during this observation period. Only infrequently will it last more than a week. The longer a fever remains undiagnosed, the greater the likelihood that it is serious and the greater the necessity for additional studies. The use of antibiotics and other agents in therapeutic trials may be part of later studies but not of initial ones. Aspirin is generally the antipyretic of choice, but it has a number of limitations.