Do you lose your sense of smell when you are infected with Covid-19?
This means that the disease will not be too severe, although sometimes there are exceptions with severe complications.
This is the main conclusion of a vast European survey coordinated by the Foch hospital in Suresnes in the (Hauts-de-Seine) and the University of Mons (Belgium) which has just been made public.
"The loss of smell is a factor of good prognosis, in the evolution of a Covid", specifies us the Dr Jérôme Lechien, head of the otorhinolaryngology department of the Foch hospital, which directed this study, with the professor Sven Saussez from the University of Mons.
Initial work on this topic was published in April 2020, and this is the continuation of their research.
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To come to this conclusion, the researchers examined the evolution of the health status of a large cohort of 1,300 patients with Covid-19.
They divided it into four groups, according to the WHO qualification, according to the level of severity.
First of all, the “light ones”, who can stay at home without worries;
the "moderates", with some difficulty in breathing;
the "severe" who need occasional oxygen supplies in the hospital, and the "very severe" who very frequently need it in intensive care and intensive care.
“The results show that among the patients who were in groups 3 and 4, ie the most severely affected, only 10 to 15% of them had a loss of smell.
On the other hand, they were 70 to 85% with this symptom in groups 1 and 2, that is to say the most benign cases ”, analyzes Dr. Jérôme Lechien.
Two months to recover this meaning
How to explain this phenomenon ?
“Our hypothesis is that the loss of smell means that the virus gets not only to the nose, but also to the central nervous system.
MRI images then show damage to the olfactory bulb, a region located at the base of the brain and which has a major role in smell.
The virus is then contained by the immune system.
This prevents it from having too much passage through the lungs and into the blood, which is the case in the most serious cases, ”adds Dr. Jérôme Lechien.
The loss of taste would have the same origin: "The ability of Covid-19 to invade the olfactory bulb and the central nervous system helps to explain the associated frequency of taste disorders," he adds.
The publication also shows that “75 to 85% of patients who lose their sense of smell recover it two months after the end of the disease.
Regarding the taste, this is the case in 90% of cases.
Among the good news, doctors find that the use of corticosteroids has good results on the sense of smell, and helps "calm the inflammation of the olfactory bulb".
A useful remedy in this period, because Dr Jérôme Lechien "sees more and more people returning to his consultation at the Foch hospital with a loss of smell, a concrete sign of the progression of the virus".
