Fever of unknown origin (FUO) has been a vexing problem for physicians for decades. The advent of imaging, functional scans, guided procedures and advanced molecular techniques has made many of the hitherto undiagnosed diseases easily diagnosable. It is important to know local epidemiology as diseases can vary from country to country or region to region making them geographically unique. Studies done in India are scarce, with variable definitions.
Methods: We recruited 300 consecutive patients presenting with classic FUO as defined by Durack and Street to a tertiary care centre in South India. A preliminary workup was done to rule out delayed diagnosis of an acute febrile illness. Potential diagnostic clues (PDCs) were identified and workup proceeded on those lines. An attempt was made to establish a confirmatory diagnosis in most cases either on the first or subsequent admissions without starting empirical therapy.
Among the 300 classic FUO in our series, infections, neoplasms and NIIDs contributed to 48%, 21.6% and 20.6% of the cases. Miscellaneous and undiagnosed causes accounted for 8.6 % and 1.6% of the cases in our series. Among the infections, Tuberculosis, Melioidosis and Visceral abscesses were the most important causes. Among the neoplasms, hematological malignancies like Non Hodgkins lymphoma, Hodgkins’ lymphoma and Leukemia were commonest and contributed to 78% of neoplasms causing FUO whereas solid organ malignancies contributed to 18% of the cases. Among the NIIDs, Systemic lupus erythematosus, Granulomatous diseases and Vasculitis contributed to 26%, 18% and 14.5% respectively. Diagnostic tests of utility included image guided biopsies (100%); CT scan of abdomen and or thorax (92.4%) and Lymph node biopsies at 72%. Mortality was 5%. PDCs contributing to each specific diagnostic category of infections, non-infectious inflammatory disease (NIID) and neoplasm were identified, a boot strapping analysis was done and algorithms were developed.
Conclusion: This is the largest series of FUO from South India. Systematic sequence of investigations without start of empirical therapy led to a diagnosis in 99.4% which is the highest in described literature. Algorithms which could be utilised in India towards a diagnosis of FUO in each specific category were constructed
O. Abraham, None
T. David, None
V. Surekha, None