RECOMMENDATIONS
Methods of Diagnosis
Under normal circumstances the paranasal sinuses are assumed to be sterile.17–19 However, the paranasal sinuses are in continuity with surface areas, such as the nasal mucosa and nasopharynx, which are heavily colonized with bacteria. Although it is reasonable to assume that the paranasal sinuses are frequently and transiently contaminated by bacteria from neighboring surfaces, these bacteria, which are present in low density, are probably removed by the normal function of the mucociliary apparatus. Accordingly, the gold standard for the diagnosis of acute bacterial sinusitis is the recovery of bacteria in high density (≥104 colony-forming units/mL) from the cavity of a paranasal sinus.20 Although sinus aspiration is the gold standard for the diagnosis of acute bacterial sinusitis,11 it is an invasive, time-consuming, and potentially painful procedure that should only be performed by a specialist (otolaryngologist). It is not a feasible method of diagnosis for the primary care practitioner and is not recommended for the routine diagnosis of bacterial sinus infections in children. However, the results of sinus aspiration have been correlated with clinical and radiographic findings in children with acute respiratory symptoms.21,,22