Acute and chronic bacterial sinusitis.

Sinusitis is one of the most common complaints resulting in physician visits in the United States. An antecedent viral infection of the upper respiratory tract is the most common presentation. Despite its prevalence, most cases resolve spontaneously. Only a small proportion develops a secondary bacterial infection that will benefit from antimicrobial therapy. This article discusses the microbiology and pathogenesis of acute and chronic bacterial sinusitis. The role anaerobic bacterial in chronic and recurrent sinusitis is emphasized, and appropriate antimicrobial regimens are discussed.