Objective: To investigate the clinical characteristics of tuberculosis (TB) first presenting as fever of unknown origin (FUO).
Methods: The clinical data of 100 cases of FUO, diagnosed as TB finally, among in-patients in Peking Union Medical College Hospital were analyzed retrospectively.
Results: (1) Sites of TB:there were 39 patients with merely pulmonary TB, 28 patients with merely extrapulmonary TB, and 33 patients with both pulmonary and extrapulmonary TB. (2) CLINICAL MANIFESTATIONS: depending on the different sites of tuberculous lesion, the clinical symptoms varied accordingly. The common laboratory findings included anemia, hypoalbuminemia, elevation of the level of ESR and C-reactive protein (CRP). (3) Methods for diagnosis: 34 cases were diagnosed by sputum smear- or cultivation-positive for acid-fast bacilli; 8 cases by histopathology; 49 cases by clinical diagnosis of TB with an effective anti-TB therapy; and 9 cases by effective diagnostic anti-TB therapy. (4) Responses to treatment: among 73 cases with complete follow-up data, only 2 cases (2.7%) died and the other cases were cured or alleviated. Fifty-five cases (77.5%) showed marked efficacy after less than 4 weeks of regular anti-TB therapy, 37 cases (52.1%) suffered adverse effects of anti-TB agents, and all of them had improved after modifying anti-TB therapy and supporting treatment.
Conclusions: The diagnosis of TB that presents as FUO is quite difficult, and the median interval time for making diagnosis is 14 weeks (3 - 77 weeks). Investigating clinical manifestations comprehensively, reviewing radiology data carefully, and eliciting microbiological and pathologic evidence of TB, are extremely important for making the correct diagnosis. In some cases, a therapeutic trial of anti-TB therapy is necessary.