Microbiology and immunology of rhinosinusitis

Abstract

Rhinosinusitis is one of the most common health care problems facing the primary care physician and results in significant heath care costs. With an increasing prevalence and incidence, it is believed that approximately 31 million Americans are affected by this condition annually [1-5]. Rhinosinusitis significantly impacts patients' quality of life and results in marked physical, functional, and emotional impairment. Thus, a good understanding of the pathogenesis, microbiology, and immunology of this illness is needed for accurate diagnosis and proper treatment. Rhinosinusitis represents a group of disorders characterized by inflammation of the nasal and paranasal sinus mucosa [6]. As such, it is presently thought that rhinosinusitis is initiated with an inflammatory insult (allergic rhinitis exacerbation, viral upper respiratory tract infection, rhinitis medicamentosa, etc.), followed by bacterial or fungal superinfection. Mucociliary clearance is the sinonasal cavity's most powerful protective mechanism through its expeditious removal of offending organisms. Once cleared from the sinonasal cavity, organisms enter the nasopharynx, which is an area devoid of mucociliary clearance, thus resulting in bacterial colonization and the possibility of retrograde sinonasal infection [7]. Bacterial colonization of the nasal vestibule with staphylococcus species (Staphylococcus epidermidis, Staphylococcus aureus) is quite common and can affect the quality of sinonasal cultures. Viruses are not considered part of the normal flora of the sinonasal cavity and are considered precursors to bacterial sinusitis. Because specific treatment approaches are crucial for the different types of rhinosinusitis as well as their different pathogens, the microbiology and immunology of rhinosinusitis are now reviewed. © 2008 Springer Science+Business Media, LLC. All rights reserved.