In monitoring the course of illness, we have used serial determinations of CRP in osteoarticular and many other invasive infections for three decades.[42–44] Some current investigators have been advocating the use of procalcitonin, another marker of inflammation, but we doubt if it adds anything to CRP, which is less expensive and easier and quicker to measure – a whole blood finger-prick sample suffices, and handy portable instruments for point-of-care tests are available. Furthermore, procalcitonin measurements might be inferior even to CRP, at least in SA.[12,45] Traditional ESR is useful in diagnostics, but normalizes too slowly to be a good yardstick in monitoring.
OM+SA and SA induce the highest CRP levels, whereas the lowest are encountered in OM. After the institution of treatment CRP continues to increase for 1 or 2 days, but then descends swiftly reaching <20 mg/l in approximately 10 days. If decreasing levels are not found by the fourth day of treatment, a complication should be suspected. CRP is even more specific to detect complications than persistent fever.
Expert Rev Anti Infect Ther. 2011;9(12):1125-1131. © 2011 Expert Reviews Ltd.