The role of infection and antibiotics in chronic rhinosinusitis.

OBJECTIVE: To review the current understanding of the role of infection and antibiotics in chronic rhinosinusitis. REVIEW METHODS: PubMed literature search RESULTS: Chronic rhinosinusitis (CRS) in adults is an inflammatory condition and the role of infection is unclear. Biofilms are present in both CRS and normal patients so their role in CRS is unknown. Sinus cultures in CRS demonstrate a mixture of aerobic and anaerobic bacteria but may be hard to interpret due to contaminating nasal flora. Staphylococcus aureus is common in CRS patients but also present in 20‐30% of nasal cultures in the normal population; eradicating this organism did not lead to symptom improvement versus placebo in a randomized controlled trial (RCT). In CRS patients who develop an episode of acute rhinosinusitis (ARS), bacteria typical of ARS can generally be cultured and require short‐course treatment. For CRS, topical antibacterial or antifungal agents have shown no benefit over placebo in RCTs, although RCTs of topical antibacterial agents have been small. Oral macrolides and doxycycline, antibiotics with anti‐inflammatory properties, are the only systemic antibiotics that have been evaluated in RCTs. One RCT found 3 weeks of doxycycline beneficial in patients with polyps but follow up was short (<3 months); RCTs of prolonged macrolide therapy have produced mixed results, and most show no benefit after cessation of therapy. Long‐term antibiotic therapy may produce side effects and select increasingly resistant flora. The American Academy of Otolaryngology—Head and Neck Surgery guidelines recommend against treatment of CRS with antifungal agents but do not comment on the role of antibacterial treatment. CONCLUSION: The role of infection in CRS is unknown, and the only well‐defined role for antibiotics is for treatment of ARS episodes or their infectious complications. LEVEL OF EVIDENCE: N/A.