Loss of sense of smell after COVID-19, what to do?

Loss of smell not only affects the condition health in general, but also significantly reduce the quality of life of patients.

Relationship between COVID-19 and olfactory disturbances

In a small percentage of people with a stuffy and runny nose, the physical blockage of the nose with mucus reduces the odor. However, the majority of COVID-19 patients with a loss of smell usually do not have a stuffy or runny nose, and so other mechanisms must be involved.

SARS-CoV-2 enters cells primarily through the interaction between the viral Spike protein (S protein) and the Angiotensin-Converting Enzyme 2 (ACE2) receptor in the target cell. Recently, scientists discovered that furin protease is also involved in the infection process because of SARS-CoV-2, which increases the infectivity of SARS-CoV-2 as well as provides a pathway for the virus to enter. into the central nervous system. The two main routes of infection are hematopoietic and neuronal – via the olfactory route (because nasal cells have a high concentration of ACE2 receptors).

In addition, another type of cell in the nose located next to the olfactory neurons called the supporting epithelial cell (susentacular cell/supporting epithelial cell) expressed ACE2. These cells support the olfactory nerve cells in the nose and can die from infection. However, loss of propagules does not lead to death of olfactory neurons but to sensory dysfunction (caused by cilia contraction), which may resolve like for the sudden loss of sense of smell.

How to handle?

Studies show that patients with olfactory dysfunction can recover 15 to 20 days after the onset of the disease, meaning that many people will improve their sense of smell on their own without needing specific treatment. how can. However, many cases of olfactory disturbances that persist beyond that time require appropriate treatment.

Here are some of the therapies offered based on scientific evidence:

olfactory training

Olfactory training is considered the only current alternative treatment for post-viral anosmia that has a solid scientific basis. The aim of this therapy is to combine memory and smell. For twelve weeks, the patient took one session in the morning before breakfast and one in the evening before dinner. Patients were advised to smell six essential oils such as lemongrass, rose, clove, rose geranium, mint, and coffee bean. They should try to recognize the smell without reading the label on the bottle.

Use caffeine

The use of caffeine for this purpose is based on its affinity for adenosine A2a receptors. Caffeine antagonizes the adenosine A2a receptor in the olfactory bulb, which is one of the major regions affected by SARS-CoV-2. Some studies show that caffeine enhances the sense of smell in people with COVID-19. The lowest recovery rates were associated with patients with underlying medical conditions such as diabetes, high blood pressure and heart disease, while those without underlying conditions recovered more quickly after drinking coffee.

Vitamin A

Retinoic acid (RA) – a metabolite of vitamin A, is one of the thyroid hormones. It is an important transcriptional regulator during tissue growth and regeneration. Vitamin A can promote olfactory nerve epithelium regeneration.

Corticosteroids

The British Rhinological Society (BRS) Guidelines recommend the use of nasal corticosteroids in patients with loss of smell for more than 2 weeks associated with nasal symptoms. However, this drug has many side effects when used inappropriately such as osteoporosis, increased risk of infection, high blood pressure, increased blood sugar, etc. The drug should only be used after consulting a doctor.

In addition to the above measures, patients need to clean the surrounding environment, avoiding dust and fumes that stimulate an inflammatory response in the upper airway.

– There is a mode nutrition reasonable, increase physical activities to improve health.

– For patients with a history of allergic diseases such as allergic rhinitis, asthma, etc., it is very important to avoid allergic agents.