[A clinical review of 449 cases with fever of unknown origin].

OBJECTIVE: To investigate the causes of fever of unknown origin (FUO). METHODS: The clinical data were retrospectively analyzed from patients with FUO hospitalized in Peking Union Medical College Hospital from January 2000 to December 2003. During that period of time, 449 cases fulfilled the criteria of FUO. RESULTS: Out of the 449 FUO cases, definite diagnosis was eventually achieved in 387 patients (86.9%). The most common causes of FUO were infectious diseases (56.8%), with tuberculosis accounting for 43.6% of cases of infection. Seventy-six patients were suffered from collagen vascular diseases (CVD): with Still's disease, systemic lupus erythematosus and vasculitis accounting for 34.2% (26/76), 18.4% (14/76) and 13.2% (10/76) of the this category, respectively. 16.5% (64/449) of the FUO cases were diagnosed as malignancy. Miscellaneous causes were found in 7.0% of the FUO cases. However, no definite diagnosis had been made in the remaining 62 (13.8%) cases until they discharged from the hospital. CONCLUSIONS: In most FUO cases the causes can be diagnosed eventually after careful analysis of clinical data. While infectious diseases, especially tuberculosis, were still the most common causes of FUO, CVD and malignancy were also major causes of FUO and the incidence of malignancy were increased with the time.