Effect of intranasal nitrilotriacetic acid trisodium salt in lowering elevated calcium cations and improving olfactory dysfunction in COVID-19 patients.

Dear Editor,

I read the article written by Mohamed H. Abdelazim et al. with great interest.

I would like to thank Mohamed H. Abdelazim et al. for their study which points up to date topic; improving olfaction in COVID-19 patients [1].

In the literature, there are studies about the different variants of the coronavirus 2019 (COVID-19) that caused much more frequent olfactory dysfunction [2, 3].

We published an article about COVID-19 and anosmia in 2020. In this study, we objectively evaluated the difference in nasal mucosal secretion between anosmic COVID-19 patients and healthy individuals, and we could not find any difference between the groups [4]. In that time period, Wuhan variant was the dominant COVID-19 variant.

The recent studies about the omicron variant of COVID-19 showed that runny nose is a common symptom that may be related to nasal mucosal inflammation [5].

These studies show us that different variants have different effects on the nasal mucosa. For this reason, I believe that the authors should specify which variant they used to work with.