Many different treatment options for chronic sinusitis (CS) exist but questions remain regarding the best options. While oral and intravenous antimicrobial therapies have traditionally been prescribed to manage CS, topical administration of these agents has gained increasing popularity over the past few years. Topical antimicrobials have the advantage of local delivery to the sinonasal mucosa and minimize the systemic effects seen with systemic agents. This is especially important in treatment of biofilms where higher concentrations of antibiotics are usually required.
Topical antibiotic delivery devices to date have included nasal sprays, irrigations, and nebulizers. Nasal spraying of topical antibiotics are not believed to be very effective. This is supported by studies that have shown that the majority of deposition occurs only in the anterior part of the nasal cavity. In addition, the nasal sprays rely on mucociliary clearance to transport the drug from the anterior to the posterior nasal cavity, and in patients with CS, their mucociliary clearance may be impaired. There are, however, other studies that found nebulization and irrigation to be effective.
Fungi can play a role in the pathogenesis of CS both in an allergic and inflammatory manner. Several recent studies that evaluated the efficacy of topical amphotericin B showed trends that were promising. However, most of the placebo-controlled studies showed no statistical difference between the treated patients and untreated controls.
Recent animal studies found that mupirocin was effective in reducing Staphylococcus biofilm mass by over 90%. Staphylococcus aureus-related acute exacerbations of chronic sinusitis in patients was also treated effectively with topical mupiricin. No success was, however, achieved with aminoglycosides in reducing Pseudomonas aeruginosa biofilm.
Since most of the initial clinical work done with topical antibiotics in CS was retrospective, prospective studies are warranted to further evaluate the utility of this approach. These should evaluate the efficacy of antimicrobials, antifungals and steroids alone and in combinations.