Etiology of Adult Patients with Fever of Unknown Origin (FUO) Observed in A University Hospital in Korea from 1998-2003

ABSTRACT

BACKGROUND: Due to advances in various diagnostic methods, recent studies reported changes in the pattern of etiology of fever of unknown origin (FUO). To identify the current pattern of the causes of FUO, we analyzed the etiology of recently diagnosed FUO at a university hospital in Korea. MATERIALS AND METHODS: We reviewed 69 cases that fulfilled the criteria of classic FUO and retrospectively analyzed the etiology and decisive methods of diagnosis. RESULTS: The etioloies of FUO were infectious disease, non-infectious inflammatory disease, malignancy and miscellaneous cases in 22 (31.9%), 8 (11.6%), 4 (2.3%) and 21 (30.4%) patients, respectively. In 15 (21.7%) cases the cause could not be identified. Among infectious diseases, tuberculosis and suspected typhoid fever were the most common causes of infection (8 case, 11.7%) with tuberculosis being the most common confirmed infection. Adult onset Still's disease (13 cases, 4.4%) and drug-related fever (13 cases, 18.8%) were the most common cause of non-infectious inflammatory disease and miscellaneous causes, respectively. Decisive methods of final diagnosis were by observation of clinical course in 35 (64.8%), radiologic examination in 10 (18.5%), serologic or biochemical test in 5 (9.3%) and tissue biopsy in 4 (7.4%); none were diagnosed by culture. CONCLUSION: Infection remains the most common etiology of classic FUO in Korea and observing the clinical course is the most commonly used method for decisive diagnosis and its importance should be emphasized in approaching patients with FUO.