fever of unknown origin in children aged 3 monthsto 14 years (ahvaz, 1998-2003)

introduction : fever of unknown origin (fuo) is defined as the presence of fever for 8 or more days in a child in which a careful history and physical examination and preliminary laboratory results failed to reveal  the probable cause of the fever. the causes of fuo are different in various geographical regions.the aim of this study was to evaluate the common causes of childhood fuo in our region. materials and methods: the medical records of all children ( 3 mo – 14 years) with final diagnosis of fuo who were admitted in two hospitals affiliated to ahvaz  jondi-shapour university of medical sciences were evaluated during 6 years retrospectively. results: 35 patients were included  in this study. the causes of fuo in these patients were: infectious diseases, 12 cases (34.28%), collagen-vascular diseases, 8 (22.85%), neoplasms, 3 (8.57%), miscellaneous, 2 (5.73%) and  undiagnosed, 10 (28.57%). the mortality occurred in  5 cases with a rate of 14.28%. conclusion: the most common cause of fuo in our region was infectious diseases and kala-azar was the main cause of fuo.