Here’s a closer look at the two sets of guidelines, the evidence upon which they are based and the differing perspectives of infectious disease scientists versus ear, nose and throat doctors. With a better understanding of the whys behind the guidelines, practitioners will be in a better position to align their own practice in an informed way.
The first key to appropriate treatment is identifying the causes of sinusitis. Both sets of guidelines tackle how to diagnose bacterial sinusitis and differentiate it from the far more common viral cases. Basically, if symptoms of purulent nasal drainage, nasal obstruction and facial pain/pressure persist for at least 10 days, or if symptoms worsen after an initial improvement (double sickening), then doctors can presume bacterial involvement.
The evidence basis for this diagnostic, based on pattern and duration of illness, is that the vast majority of cases of sinusitis are viral in origin. Studies have shown that up to 2 percent of all viral sinusitis episodes are complicated by bacterial infection (J Allergy Clin Immunol. 1992;90:457-462). After 10 days of illness, about 60 percent of cases have a bacterial component (Clin Infec Dis. 2004;38:227-233).