Background: Intranasal steroids are the first line of treatment for chronic rhinosinusitis. Although contamination of adjunctive devices (e.g. irrigation bottles) has been much investigated, little is known about nasal contamination of the metered-dose spray bottles used to deliver intranasal steroids, and the potential influence on disease chronicity.
Methods: Twenty-five prospectively recruited patients with stable chronic rhinosinusitis underwent microbiological analysis of their nasal vestibule and middle meatus and also of their steroid bottle tip and contents. Additionally, bottle tips were inoculated in vitro with Staphylococcus aureus and various sterilisation techniques tested.
Results: For 18 of the 25 (72 per cent) patients, both nasal and bottle tip swabs grew either Staphylococcus aureus or coagulase-negative staphylococci. Staphylococcus aureus was cultured from 7 of the 25 (28 per cent) patients, and 5 of these 7 had concomitant bacterial growth from both nose and steroid bottle. Thus, the cross-contamination rate was 71 per cent for Staphylococcus aureus infected patients and 20 per cent overall. Sterilisation was effective with boiling water, ethanol wipes and microwaving, but not with cold water or dishwashing liquid.
Conclusion: Nasal steroid spray bottle tips can become contaminated with sinonasal cavity bacteria. Simple sterilisation methods can eliminate this contamination. Patient education on this matter should be emphasised.