Camila was born without a sense of smell, and María lost it to COVID: "I can't even smell my own sweat."

Camila Gallardo is 21 years old and from Argentina. As a child, she remembers family and friends telling her, "Look how good this perfume smells," but to her, the scent was nonexistent. "I have no sense of smell," she would reply, receiving strange looks and disbelief. However, it was only recently that she learned that her condition had a name: anosmia, the complete loss of smell.

"I'd like to know what flowers or wet earth smell like ," she confesses. Although she also jokes: "It's nice to live without the smell of rot or sewage. I've gotten used to living with anosmia and I don't suffer from it." She also believes there's a lack of awareness on the issue. "If it's congenital, as in my case, there's no way to restore your sense of smell," she opines.

At 54, María Undabarrena has a similar story to Camila's, but in her case , COVID was the culprit of her anosmia . "In December, it will be five years. I've always had a spectacular sense of smell, with a great range of odors , but as a result of the coronavirus, my eldest daughter and I radically lost our sense of smell and taste," she explains.

That is to say, María also suffers from ageusia , a complete loss of her sense of taste. "We simply thought we would recover it once the virus passed, but that's how it is. Eating meat has become impossible; when you lose the taste , it's like chewing a belt ," she points out. "We have to be very careful that what we eat is always in good condition, since several times we have eaten something that has gone bad and haven't realized it until someone at home told us," she adds.

Another aspect she highlights is that over the years she and her daughter have gone through different phases : "A few months after the positive test, we began with the sensation that for a few thousandths of a second we perceived a smell , but it stayed for an instant, the good smells are gone forever. We don't smell ammonia, or bleach, or gasoline, or even our own sweat . Other times we perceive a smell that doesn't exist or we confuse them: it smells like burnt cables and it's bread in the toaster."

Sometimes the sensation is "so unpleasant" that hunger vanishes . "I never imagined that, being such a good cook and enjoying cooking so much since I was a child, I would end up feeling like it had become a real ordeal . I've lost the joy it gave me," she says.

And these are not the only problems he mentions : "As time goes by, you discover that, by losing your sense of smell and taste , you also begin to isolate yourself. If you close your eyes, you are no longer able to perceive the presence of others through their scent. Before, when you woke up, without needing to open your eyes, your sense of smell would tell you that someone was next to you. You also recognized your home as soon as you entered: that characteristic smell that envelops you, calms you and confirms that you were in a safe place."

"We all remember those smells that take us back in time: grandma's house, the smell of a baby, the fragrance that simply reminds us of life. Because yes, life also has a smell, and we aren't fully aware of it until we lose it," he insists. He also comments that he's always explaining things to the same people who don't understand how things can go on like this: "They insist that there must be a solution ."

However, both underwent olfactory training for 18 months and have undergone several tests: "They come out fine, but you ask for a solution and they tell you there isn't one. My daughter has been told that there's some possibility of recovering her sense of smell when she gets pregnant due to the regeneration that occurs in the body." "We are invisible. A blind person isn't constantly asked 'do you see?'; nor is a deaf person asked 'do you hear it?'. Our disability goes unnoticed by the world time and again," she concludes.

The oldest sense

For his part, Alfonso del Cuvillo Bernal , an otorhinolaryngology specialist in the rhinology and asthma unit at the Jerez University Hospital , states that, from the perspective of evolutionary biology, smell is the oldest sense of all living beings.

" Smell disorders can be quantitative, where the ability to smell is partially or totally lost, or qualitative, where the olfactory sensation is altered without losing the ability to smell. With anosmia , no smell is perceived , and with hyposmia , it is partially lost, meaning more olfactory stimulation is needed to perceive the smell," says the president of the rhinology committee of the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC).

He goes on to say that the cause can be multifactorial, although the most common is a viral infection . "Normally, it produces a reversible disorder with complete recovery, but in other cases, such as with COVID-19 , it can leave persistent after-effects such as an altered sense of smell. Other causes include head trauma that can damage the roof of the nasal cavity, where the olfactory mucosa is located, or other chronic inflammatory disorders such as rhinitis or chronic rhinosinusitis, which affect a very high percentage of the population," he notes.

Consequences and therapies

Regarding the consequences, he lists the following: "It detects substances that are hazardous to health without the need for contact ; it is the sense with the greatest discriminatory capacity. Furthermore, it is known that the information transmitted by the olfactory nerves is distributed throughout many brain areas that are involved in emotional processing and various bodily functions such as appetite, thirst, sleep and reproduction . Many neurodegenerative disorders that affect memory or intellectual functions present an olfactory disorder as an early symptom, since good memory function is essential to identifying smells."

His answer to whether there is a cure is clear: it depends on the source. "In the case of inflammatory processes such as colds, rhinitis, and rhinosinusitis , treatment is aimed at improving the inflammation , which, on the one hand, prevents odorants from reaching the olfactory nerve sensors in the roof of the nasal passages, and on the other, temporarily or permanently damages these sensors. If there has been damage to the olfactory nerve, as in head trauma, treatment is more complicated," he explains.

"After COVID, there has been greater awareness regarding these disorders."

He also emphasizes that a form of treatment that is increasingly being used and with better results is olfactory training or re-education: " Olfactory sensory neurons are continuously regenerated and the brain has great plasticity , so olfactory stimulation and structured training have been shown to have very good results in both qualitative and quantitative disorders, although in some cases, with significant neurological damage, the optimal result is not achieved."

Finally, he points out that after COVID , there has been greater awareness regarding olfactory disorders, making them a more frequent reason for consultation than before the pandemic.