The invention involves methods and formulations for treating or preventing rhinosinusitis, including but not limited to, bacterial-induced, viral-induced and/or fungus-induced rhinosinusitis in mammals, and/or rhinosinusitis not induced by an infective agent, such as bacteria, fungus or virus. In one embodiment, the formulation of the present invention comprises an anti-inflammatory agent (e.g. fluticasone propionate) having a specific particle size distribution profile. The formulation may also comprise an antifungal agent, antibiotic or antiviral agent.
