Vanilla extract that stinks of “burnt rubber”, lemon that only smells “sour”, fir branches that give off scents… of mint? Smells merge in the nostrils of thousands of people infected with COVID-19. As the science of this curious symptom of the coronavirus becomes clearer, hope for an effective treatment is now looming.
As early as 2020, loss of smell has been described as a consequence of COVID-19. As we can see today, this new fragrance-free normal can become permanent. The professor at the University of Quebec at Trois-Rivières, Johannes Frasnelli knows something about it. He has studied the science of smell for decades, and for the past two years has been trying to find a solution for COVID-19 patients deprived of their sense of smell.
According to him, “60% of infected people have a smell disorder during the acute phase of the disease. And 10% of these 60%, so 6%, have a longer-term smell problem. These figures are from 2021, and it appears that this proportion is lower for Omicron victims.
The cause of this evil is now known: the virus invades and then destroys human cells that contain the ACE2 protein. And it turns out that the cells of the nose are filled with it. What’s more, “the nose is the first point of contact for the virus. It is for this reason that the cells in the nasal mucosa are affected in a very important way”. Then, once the nostrils are affected, the neurons that link the nose to the brain wither away due to lack of stimulation, which often leads to long-term disability.
The intensity of destruction of these cells in the nose causes different levels of complications. We speak of “anosmia” when there is complete disappearance of the sense of smell. Others suffer from ‘parosmia’, which means that meaning is altered and everything ‘smells weird’. Finally, many see their sense of smell diminished, which is called “hyposmia”.
Life for patients with parosmia can become very bland, even nauseating. Everything takes on a smelly hue. “The perceived smell is difficult to describe, it’s something very unpleasant, like burnt rubber,” describes Johannes Frasnelli, who is also the author of the book. Smell, sniff, smell. The unsuspected powers of smell.
Nightmare of cooks, anosmia does not cancel the sense of taste, but certainly weakens it, explains the specialist, because the nose makes it possible to detect “finer tastes”. For example, “if you taste an apple and a pineapple, both taste sweet, both are a little tart, but the scent, I perceive it with my nose”.
Hope
Rehabilitation techniques are gradually emerging for the relief of patients deprived of smell, and the results are already being felt.
Mr. Frasnelli’s team notably re-educates the noses of volunteers through the daily sniffing of strong odors. Morning and evening, the patient must inhale perfumes in each of the nostrils and then in the whole nose at the same time.
“Citrus, rose, eucalyptus, clove, spicy, floral, fruity, aromatic. We try to cover the spectrum of odors,” he explains.
“This olfactory training can improve the sense of smell”, confirms the neuropsychologist. He concedes, however, that the biological process that explains this healing “is not yet fully understood” by specialists in the field.
He also invites all those who have lost part of their sense of smell to participate in his research conducted at the Department of Anatomy of the University of Quebec at Trois-Rivières.
This text is taken from our newsletter “Coronavirus mail” of March 14, 2022. To subscribe, click here.
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