<unk>  of the disease is different for different etiologies of FUO. It also depends on the age of the patient, environmental and occupational exposure, Immune system of patient,  Socioeconomic status.
Infectious causes are more prevalent in Immunocompromised individuals and those living in underdeveloped countries while non infectious causes are more prevalent in immunocompetent individuals and those living in developed countries.
Fever of unknown origin epidemiology and demographics
Fever of unknown origin classification
Paratyphoid fever laboratory findings
Staphylococcal scalded skin syndrome laboratory findings
Adult-onset Still's disease laboratory findings
Typhoid fever laboratory findings
Stevens-Johnson syndrome laboratory findings
Trench fever laboratory findings