The Classical Fever of Unknown Origin in Adult Patients Admitted to Dezful General Hospital during 2018-2020

Fever of unknown origin (FUO) is one of the clinical challenges in medicine. Most causes of FUO include infectious diseases, malignancies, non-infectious inflammatory causes, and unknown factors, but this prioritization may change under the influence of various factors such as geographic area, age, and access to laboratory-diagnostic facilities. The aim of this study was to determine the frequency of causes of FUO in this area in order to suggest a better clinical approach to achieve a faster diagnosis in patients with fever of unknown origin.

In this cross-sectional, descriptive study, we studied all files of patients who admitted to Dezful General Hospital with an initial diagnosis of FUO during 2018-2019. In descriptive statistics, for qualitative variables, frequency table (percentage) and graph and for quantitative variables, central and dispersion indices including mean and standard deviation were used.

The most common causes of FUO were infectious agents (50%), non-infectious (26.1%), unknown (13%) and malignancies (10.9%). Among the infectious agents, the highest frequency was related to the diagnosis of pneumonia, sepsis and extra pulmonary tuberculosis. About 71% of patients are diagnosed with non-invasive methods. No significant relationship was found between the four main causes of FUO and other variables during the analysis using Chi-Square Tests.

Although the pattern of causes of FUO in this study is compatible with most medical sources, but we suggest that in order to achieve a faster diagnosis of patients admitted with FUO in this area, always common and endemic diseases such as tuberculosis and thyroiditis and unusual clinical manifestations of some syndromes should be considered.