FEVER OF UNKNOWN ORIGIN

Fever of unknown origin (FUO) is defined as continuous fever of at least 3 weeks duration with daily temperature elevation above 101 F (38 Cº) and remaining undiagnosed after one week of intensive study in the hospital, or as temperature greater than (38 Cº) persisting for at least for 3 weeks in patients whom the history, physical examination, blood count, urine analysis and chest films fail to indicate the diagnosis.

Regardless of which of these criteria is employed, the diagnostic approach to FUO must be individualized for each patient. The requirement of fever of 3 weeks duration for the diagnosis of FUO is most important because it eliminates from consideration most viral and bacterial infections as well as other self- limited diseases associated with fever.

Causes of fever of unknown origin

Most patients with FUO do not have a rare disease but usually suffer from common disorders that are difficult to diagnose because they present atypically. In approximately 5 - 10 % of the cases, the cause is unknown.

Laboratory tests:

- CBC                                                 

- ESR                                                 

- CRP

- Widal & Brucella                                         

- Urine Examination & C/S                

- Stool Examination & C/S                  

- Blood Culture                                 

- CMV (IgG & IgM)                          

- HIV

- Film for Malaria

- EBV Ab (IgM & IgG)

- SGPT

- ASOT

- ANA

- Throat Swab C/S

- T3, T4 & TSH