Fever of Unknown Origin inTurkey

Abstract. Background: The etiology of fever of unknown origin (FUO) includesprimarily infectious, collagen-vascular and neoplastic diseases.The distribution of the disorders causing FUO may differaccording to the geographic area and the socioeconomical statusof the country. Moreover, the developments in radiographic andmicrobiologic methods have changed the spectrum of diseasescausing FUO. Materials andMethods: We reviewed 117 cases that fulfilled the criteria of FUOfollowed in our department during the period 1984 to2001. Results: The etiology of FUO was infectious diseases in 34% of thepatients, collagen-vascular diseases in 23%, neoplasms in 19%and miscellaneous diseases in 10%. In 14% of the cases theetiology could not be found. The three leading diseases weretuberculosis (24%), lymphomas (19%) and adult-onset Stillsdisease (11%). Tuberculosis was found to be a more common causeof FUO than reported in studies in developed countries. Invasiveprocedures helped to establish the diagnosis in 50 out of 92patients (43%). As a final diagnostic procedure, laparotomyaided the establishment of a diagnosis in 15 out of 20 patients(75%). Conclusion: Although the relative rate of infectious disease asetiologic category is less commonly encountered, infectiousdisease, especially tuberculosis, remains a common cause of FUO.Although several diseases may lead to FUO, lymphomas,adult-onset Stills disease and particularly tuberculosis shouldbe considered in the differential diagnosis of a patientadmitted with FUO.