London, UK - Scientists believe to have found out why many Covid-19 patients temporarily cannot smell anything.

Their research results might even lead to a new approach for treating infected people, as the experts from the Johns Hopkins University School of Medicine write in the European Respiratory Journal.

For the study, they examined tissue removed during nose surgery from 23 patients. The patients, who were not infected with coronavirus, had been operated on for tumors and chronic sinusitis.

The researchers were able to detect extremely high doses of the enzyme ACE-2 (Angiotensin Converting Enzyme II) in the samples - specifically, in precisely the area of the nose that is responsible for smell.

The enzyme is believed to be the gateway for the coronavirus to enter cells in the body, something also indicated by other studies.

The results must now be confirmed by further investigations, said Andrew Lane from Johns Hopkins.

"If that's the case, we might be able to fight the infection with antiviral therapies administered directly through the nose."

Tobias Welte, a physician from the Department of Pneumology at the Hanover Medical School who was not involved in the research, described it as a "clever study" that could explain the loss of smell in many infected people and also provide new treatment options. However, he also believes that further research is needed.

Covid-19 can cause very different symptoms, and some patients report the temporary loss of smell and taste.