Digestive endoscopy in Diagnostic Medicine

Fever of Unknown origin (FUO) poses a diagnostic dilemma for most physicians especially when a thorough diagnostic workup is inconclusive. It was defined by Beeson and Petersdorf in1961 as a fever that is greater than 38.3 degrees Celsius (°C), persisting for a period longer than three weeks with a failure to reach a diagnosis despite one week of inpatient investigations [1]. The most common etiologies of FUO are infections (2154%), noninfectious inflammatory causes (13-24%), neoplasms (6-31%) and other causes (4-6.5%) [2]. Both non-invasive and invasive diagnostic tools are thought to have pertinent diagnostic value for determining the origin of the fever, but none of these diagnostic tests have sufficient sensitivity or specificity when they are performed in patients with no typical findings or symptoms [3].