An alteration in the quality of taste and smell, which leads to a different perception of smells and flavors that were usual only a few months earlier. It is a ‘legacy’ that Covid leaves to a percentage of healed that can reach almost 10%. And which, fortunately, is transitory for the vast majority of people, but with extremely variable duration, ranging from a few weeks to over a year, if no ad hoc therapies are made. To trace the picture of the particular disorder that sometimes accompanies those who have overcome the coronavirus infection, is Giulio Cesare Passali, researcher of Otolaryngology at the A. Gemelli Irccs University Hospital Foundation in Rome, based on studies carried out on data of approximately 2,000 patients, observed at the post-Covid Day Hospital of the Roman Polyclinic. As for the link between smell disorders and Covid, on the observed patients “there is an incidence of around 45% of people who declare they had them in the acute phase of the infection. Of these, about 30% continue to have them at the time of the check-up, that is at a distance from the acute phase that can range from 2 to 6 months. By doing the tests on the olfactory function, however, the results are generally good, with normal or slightly altered data. Sometimes patients declare they have problems with smell even if it is not quite so. And we can divide them into two different groups: one party has a psychological problem because he does not realize he smells, struggles to regain normal perception after anosmia; in a on the other hand, however, the alteration remains but in terms of quality, not quantity “. This is due to the fact that the virus, continues Passali,” does not seem to affect the olfactory neurons, but the supporting cells. The epithelial cells. in which the neuron i are inserted into our nose. It is a bit as if the roots were discovered in a plant. In practice, there is no soil that gives nourishment to these neurons which, therefore, do not function in the usual way. And this is what gives an olfactory sensation that is not normal: the odorous molecule reacts with the odor receptors with a chemical reaction, but if you change the soil in which the reaction occurs, the result also changes. That altered taste is related to this. In technical terms, an atrophic rhinitis is created – he explains – an alteration of the nasal mucosa that affects the olfactory function “. This is a condition, continues the expert,” reversible almost in all cases, with a recovery 99.6%. What varies a lot are the times. There are patients who recover after a few weeks, some after a few months, others after a year or more “. What seems to be absolutely contraindicated” are nasal cortisone therapies that lengthen recovery times or even worsen the olfactory situation ” On the other hand, “nasal rehydration therapies, which is done through washing of physiological solution and local substances based on hyaluronic acid”, concludes Passali, are useful.