Laboratory and imaging studies have limited value for the diagnosis of acute rhinosinusitis (ARS), and routine use of individual tests cannot be recommended, according to the results of a comprehensive, systematic review of the literature undertaken to determine the accuracy of laboratory and imaging studies for ARS (Br J Gen Pract. 2016;66:e612–e632).
Researchers found that radiography (LR+ 2.0, LR- 0.3) and ultrasound (LR+ 1.7, LR- 0.4) had only modest accuracy for the diagnosis of acute bacterial rhinosinusitis (ABRS), said Mark H. Ebell, MD, professor of epidemiology at the University of Georgia Health Sciences Campus in Athens, and lead author of the study,
The review included studies of patients who presented with or who were referred for suspected ARS. Using antral puncture as the reference standard, the investigators assessed the accuracy of the diagnostic tools used in each of these studies.
Dr. Ebell did say that their evidence showed that testing for C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) both had modest overall accuracy: investigators found that a CRP of >20 mg/L (LR + 2.9) and an ESR of >30 (LR+ 4.1) significantly increased the likelihood of ABRS.
The study also showed that “evaluating nasal secretions for evidence of leukocyte esterase or nitrates is promising,” said Dr. Ebell. A dipstick of nasal secretions for leucocyte esterase was highly accurate (LR+18.4, LR-0.17), but further study needs to be done to validate the finding.
Given the current evidence, Dr. Ebell said that point-of-care CRP testing, which is widely used in Europe, should help clinicians identify patients more likely to have ABRS.