Diagnostic utility of clinical and epidemiologic features in fever of unknown origin

Abstract

Objectives: To assess the diagnostic utility of clinical features in the major diagnostic categories of Fever ofunknown origin (FUO).Methods: One hundred and thirty-three patients meeting the classic criteria of FUO were included in the study.A structured diagnostic protocol was used in all cases. Sensitivity, specificity, positive and negative predictivevalues (PPV and NPVs), and likelihood ratios of positive and negative tests (LR+ and LR-) were estimatedwith 95% confidence intervals (95% CIs) for all clinical findings.Results: Clinical and epidemiologic features with best diagnostic utility indexes for the three major diagnosticcategories were: weight loss of 15 pounds or more (sensitivity, 68.4%, 95% CI: 52.33-84.52), pallor of theskin and mucous membranes (sensitivity, 65.7%, 95% CI: 49.39-82.19), prior medical history of cancer (PPV,63.6%, 95% CI: 30.66-96.61; LR+, 4.38, 95% CI: 1.36-14.09), lymphadenopathy (LR+, 2.2, 95% CI: 1.11-4.74), for neoplasms; arthritis (PPV, 72%, 95% CI: 51.84-93.61), prior family history of collagen diseases(PPV, 100%, 95% CI: 91.67-100.00), neurologic disorder (LR+, 5.1, 95% CI: 1.37-19.68), myalgia (LR+, 4.1,95% CI: 1.45-11.88) and skin lesions (LR+, 3.0, 95% CI: 1.51-6.22) for noninfectious inflammatory diseases;weight loss of 15 pounds or more (sensitivity, 50%, 95% CI: 27.91-72.09), epidemiological history of previoustuberculosis or tuberculosis exposure (LR+, 9.0, 95% CI: 1.76-46.77), and jaundice (LR+, 2.73, 95% CI: 0.7-10.63) for infections.Conclusions: We identified clinical data emerging from the anamnesis and physical examination that may helpto guide the diagnostic process in FUO.