Procalcitonin and other markers of infection. What should be their role in clinical practice?

Clinicians are always faced with a decision when confronted with a febrile patient; they must decide between what is an infectious condition and what is not, and between what merits hospital observation, what requires empirical antibiotic treatment and what needs outpatient follow-up. In this respect, judgement based on medical history and physical examination outweigh the predictive value of various laboratory markers of infection, as the latter generally reflect a nonspecific reaction of the host to widely different infectious and inflammatory stimuli. In the evaluation of specific subgroups of patients, e.g. those in the intensive care unit, laboratory tests should also preferably form a continuum with medical history and physical examination, aimed at clarifying host condition, the setting and the source of a possible infection.