The authors, Dr. John S. Schneider of Washington University School of Medicine, St. Louis, Missouri, and his colleagues, review the current evidence on the potential effects of nasal saline irrigations and their adjuncts with viral upper respiratory illnesses in an opinion piece in JAMA Otolaryngology-Head and Neck Surgery, writing that it has been unclear as to whether or not topical nasal saline irrigation mitigates viral effects, augments viral transmission or has no impact at all.

The Science
Nasal rinses physically disrupt the viscous surface layer, removing mucus and particulate matter, and increase hydration of the deeper aqueous layer, thereby improving underlying ciliary beat frequency and reducing local inflammatory mediators. These effects can be particularly helpful during a viral respiratory infection. The best tonicity of saline used for nasal rinses remains unclear, as does the potential value of adding steroid compounds to saline irrigations. Potential risks of nasal irrigation should also be taken into account, including the possibility that irrigation might increase viral shedding (thus transmission) and that the nasal-rinse bottle might serve as a vector for transmission.

“Thus, patients should practice good hand hygiene and decontaminate the surrounding surfaces (e.g., sink, counters) and plastic rinse bottle to prevent subsequent infection,” the authors note. “Given the safety profile of these therapies, hypertonic saline nasal irrigations should be encouraged for patients and health care workers especially. For our patients with chronic rhinosinusitis, continued use of steroid irrigations should be encouraged. Emerging research is expected to shed further light on saline irrigation’s protective and therapeutic effect on COVID-19.”.

Benefits of Nasal Irrigation
“The benefit of saline nasal irrigation for preventing and treating COVID-19 infection is yet to be established, but it is worth considering its use, as it is safe and cheap and has demonstrated benefit in treating viral and allergic rhinitis,” said Dr. David King of the University of Queensland in Australia, who recently reviewed the role of nasal saline irrigation in a variety of settings, and who was not involved in the Washington University report.

Dr. Rakesh K. Chandra of Vanderbilt University Medical Center in Nashville, Tennessee, who recently reviewed the use of nasal saline irrigation in chronic rhinosinusitis, noted that “All of these treatment decisions are based on risk versus harm considerations. With proper precautions (distilled water, cleaning the bottle and surrounding surfaces, as the authors note), irrigations are valuable with little to no risk. Hypothetically, rinses with iodine might carry less risk of disseminating virus since any collateral droplets would have the iodine. There may also be a role for surfactant irrigations, which are essentially dilute soap solutions. These are known to disrupt the viral capsid (the protein shell that protects the nucleic acid of a virus).”

The original report published in JAMA was an opinion piece. Dr. Schneider did not respond to a Reuters Health request for comments after the two other doctors weighed in.

Reference: Article at Medscape.com – 31 July 2020