On the basis of strong research evidence, the pathogenesis of
sinusitis involves 3 key factors: sinusostia obstruction, ciliary dysfunction, and thickening of sinus secretions. On the basis of studies of the microbiology of
otitis media, H influenzae is playing an increasingly important role in the etiology of
sinusitis, exceeding that of S pneumoniae in some areas, and b-lactamase production by H influenzae is increasing in respiratory isolates in the United States. On the basis of some research evidence and consensus,the presentation of acute bacterial
sinusitis conforms to 1 of 3 predicable patterns; persistent, severe, and worsening symptoms. On the basis of some research evidence and consensus,the diagnosis of
sinusitis should be made by applying strict clinical criteria. This approach will select children with upper respiratory
infection symptoms who are most likely to benefit from an
antibiotic. On the basis of some research evidence and consensus,imaging is not indicated routinely in the diagnosis of
sinusitis. Computed tomography or magnetic resonance imaging provides useful information when complications of
sinusitis are suspected. On the basis of some research evidence and consensus,
amoxicillin-
clavulanate should be considered asa first-line agent for the treatment of
sinusitis.