Nose, the air-purifier of the airways is considered the first line of defence against various airborne particles including microbes, impurities, and irritants. The non-pathogenic and pathogenic antigens are mainly removed by the nasal mucosa. However, if an antigen manages to cross this layer of defence, non-specific (phagocyting cells like neutrophils and macrophages and complement activation) and specific (formed by the antibodies, secretory IgA and IgG and immunocompetent cells in the nasal mucosa) immunological defence mechanisms occur. Failures in these defence mechanisms, may cause allergy or result in upper respiratory infections.¹

Therefore, it is important to keep the nose in good condition by cleaning it regularly. For this purpose, the use of saline has been widely advocated. Saline helps in mechanical cleaning, dilution of nasal mucus, and induction of rhinorrhea. Besides, it has displayed positive outcomes in terms of ciliary clearance.² Nasal saline sprays are often recommended as their tolerability and adherence are much better than other modes of delivery. Thus, for people who are not willing to try saline solution or are unsatisfied with the saline irrigation process, saline spray is a reasonable alternative.³

References

1. FokkensWJ, Scheeren RA. Upper airway defence mechanisms. PaediatrRespir Rev. 2000 Dec;1(4):336-41.
2. de Mello Júnior JF, de Godoy Mion O, de Andrade NA, et al. Brazilian Academy of Rhinology position paper on topical intranasal therapy. Braz J Otorhinolaryngol. 2013;79(3):391-400.
3. Egan M, Hickner J. Saline irrigation spells relief for sinusitis sufferers. J FamPract. 2009;58(1):29-32.