ABSTRACT
Fever is only a symptom or sign of disease, although it is important enough to direct the clinician to find its cause in order to diagnose and treat the condition without delay. In some disorders fever is such a prominent manifestation that the condition is named in relation to certain characteristics of the fever. Fever as a cardinal manifestation of disease has been known since antiquity. V. Menkin, in 1943, isolated from inflammatory exudates a substance called “pyrexin”, which caused fever when injected into rabbits. During the 1930s many retrospective and prospective studies on prolonged fever were carried out. In a multidisciplinary approach to a complex topic of unexplained fever, some degree of overlap in the various chapters is inevitable. In 1961 R. G. Petersdorf and P. B. Beeson published their classic prospective study of fever of unexplained origin (FUO). Computed tomography has been shown to reduce the number of negative biopsies in patients with FUO.
