About 5% of the world’s population is affected by anosmia, a sensory disorder brought to the fore with the Covid-19 pandemic. Every February 27 is World Anosmia Awareness Day. The opportunity to let people know that SARS-CoV2 is not the only cause of loss of smell!
Global Awareness Day: What is anosmia?
Anosmia is complete loss of smell, which may or may not be associated with ageusia, which is the complete loss of taste. This sensory disorder has its World Awareness Day every February 27. Until then, this event was almost completely unknown in France, but the arrival of Covid-19 made the whole world aware of what anosmia was. In effect, loss of taste and smell is now one of the best-known symptoms of SARS-CoV2 infection.
First, we must distinguish between anosmia, where the ability to smell odors is completely lost, temporarily or permanently, and hyposmia, which is the partial loss of smell. Anosmic patients not only have a loss of smell, because their perception of tastes is altered since smell and taste are intimately linked. Generally, anosmic subjects perceive salty, sweet, sour or bitter tastes in the normal way, but describe a modified taste, which often has consequences on their diet.
Anosmia, linked to Covid-19, but not only!
Before the arrival of Covid-19, anosmia was estimated to affect regarding 5% of the world’s populationwith very different causes:
- Head trauma;
- The existence of a tumor in the brain or in the ENT pathways;
- Irradiation of the head and neck;
- Sinus surgery;
- Certain viral infections (viruses other than SARS-CoV2 cause loss of smell, including seasonal flu);
- Alzheimer’s disease ;
- A congenital cause (from birth);
- Taking certain medications.
In terms of mechanisms, the loss of smell can be linked to the presence of a nasal obstruction, a lesion of the olfactory epithelium or even in the event of damage to the olfactory nerve. When the nerve is affected on only one side (unilateral anosmia), the patient often does not realize it, because the non-injured side compensates and allows the perception of odors.
No treatment available for anosmia
The management of anosmia is closely linked to its cause and its characteristics (duration, occurrence, etc.). Sometimes, treating the cause allows the patient to regain the perception of odors. In the event of neurological lesion or during aging, the damage can however be irreversible. In the majority of cases, the anosmia remains reversible and the patient recovers his olfactory capacities in a few weeks or a few months. Skills essential for food, social life and health. Smell is also essential to detect certain dangers, such as a burning smell in the house!
With the Covid-19 epidemic, has also developed olfactory rehabilitation, which allows the patient to be accompanied in the gradual recovery of their olfactory and taste abilities. It allows in particular to correct the disorders of bad perception of the smells and the tastes.
On the other hand, no specific treatment exists for anosmia. The sense of smell is precious on a daily basis, and it should be preserved as well as possible, because anosmia is a major factor in the deterioration of the quality of life.
Estelle B., Doctor of Pharmacy
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