We collected testimonies from people who lost their sense of smell, some due to covid-19. But an increasingly popular therapy offers a light at the end of the tunnel

« It is as if an invisible barrier separates me from reality, » said Saulo. « It’s as if my memories have been erased, » Ana said.

« Everything smells the same to me, » Virginia said.

Saulo and Ana live in Brazil, Virginia is Mexican but resides in the United States. All three lost their sense of smell, and in some cases taste, due to the new coronavirus.

BBC Mundo contacted them through AbScent.org, a website that offers help to those who are left, totally or partially, without the ability to perceive odors.

« On March 13, I had about 1,500 people in the Facebook group, » Chrissi Kelly, founder of AbScent, told BBC Mundo.

“Now I have three Facebook groups with about 11,000 members in total. Suddenly they started contacting me from Iran, Italy, Spain and then many people from Latin America ”.

« The site became a barometer of the impact of the coronavirus. »

Science Photo Library It is essential to perform the smell rehabilitation exercises while maintaining concentration « instead of thinking about what you will do the rest of the day. »

In AbScent, users find information about a therapy that, although it was already offered before covid-19, is gaining popularity due to the pandemic.

Therapy is the “olfactory training“, A series of exercises to recover the perception of smells, and in the case of many people, a sense of normality in their lives.

What is the loss of smell and what is its emotional cost?

How effective is olfactory rehabilitation and what is its scientific basis?

Loss of smell and its causes

Numerous investigations established a connection between smell problems and the new coronavirus.

“In our study, which was carried out including 15 hospitals throughout Spain, of 989 patients with covid-19 a 53% had altered smell“Adriana Izquierdo Domínguez, allergology specialist at the Teknón Medical Center in Barcelona and member of the Spanish Society of Otorhinolaryngology (SEORL), told BBC Mundo.

But the new coronavirus is only the latest in a long list of possible causes.

Courtesy Saulo SegretoSaulo Segreto has been training for more than four months. « After losing my sense of smell, I feel as if an invisible barrier separated me from reality. »

Patricia Portillo Mazal, otolaryngologist and smell and taste specialist at the Italian Hospital in Buenos Aires, explained that “one of the most frequent causes of loss of smell are viral infectionslike colds and flu ”.

Another common origin are blows to the head or face that damage some part of the olfactory system, added the expert.

Sometimes the reason for the loss of smell is not identified, which can also have different degrees.

« There is talk of anosmia when there is no smell and hyposmia when perception is partial, ”explained Portillo Mazal.

« But sometimes the most limiting thing is still the call parosmia, the distorted smells, when a coffee smells different to you from what you remembered, many times as something unpleasant ”.

“And within the parosmia there is even the phantosmia, which is to smell a smell that is not there but that you perceive ”.

The emotional impact

Loss of smell can profoundly affect well-being, as the story of Chrissi Kelly, the creator of AbScent, illustrates.

Kelly, who was born in the United States and resides in England, lost her sense of smell from a viral infection in 2012.

« Between about six and nine months later I fell into a deep depression, » he told BBC Mundo.

“There is something fundamental that I would like people to understand. Losing your sense of smell is a blow to your well-being, it affects every aspect of your life. Steeth as if you lose the sense of whoandyou were« He added.

Courtesy Chrissi KellyChrissi Kelly is the founder of AbScent. “There is something fundamental that I would like people to understand. Losing your sense of smell is a blow to your well-being, it affects every aspect of your life ”.

After consulting doctors who « looked into your nose without giving you solutions, » Kelly began looking for information and attending specialist conferences.

In one of them he found Thomas Hummel, an expert at the Center for Smell and Taste at the University of Dresden in Germany.

Hummel was the first scientist to publish, in 2009, a study evaluating the effectiveness of olfactory training.

« When I told my story to Hummel, he listened compassionately for half an hour. It was the first time that I spoke with someone who understood me ”.

Kelly began attending courses that the German expert gave to specialists and in 2015 ended up founding AbScent.

The site has a YouTube channel with explanatory videos and now has guides in Spanish and Portuguese for users in Latin America.

Saulo, Ana and Virginia

Many of AbScent’s readers, such as Saulo, Ana and Virginia, claim to have found on the site that feeling of support that Kelly experienced when she was heard by Hummel.

“I went to three ENT specialists, a neurologist and a pneumologist. They even gave me an antiepileptic drug that left me sick. And through tireless searches on the internet I came to AbScent, which it was essential to keep calm“Saulo Segreto recounted from Rio de Janeiro.

Courtesy Ana CarboneAna Carbone: « I feel despondent when I do not perceive smells like that of my daughter, a perfume, or not knowing if there may be a gas leak. »

Saul suffers from parosmia. « For me all things fried smell like burning, » he said.

« Lately I have a horrible smell in a lot of things. Leaves me nauseous“Said Ana Carbone, from Sao Paulo, who suffers from the same.

« And I feel upset by not perceiving smells like that of my daughter, a perfume, or not knowing if there may be a gas leak. »

In the case of Virginia Mata, some experiences are even difficult to describe.

“I went on August 23 from not smelling anything to perceiving a strange smell. Mmy brain doesn’t know how to process it to name itIt’s just kind of weird. « 

How is the training

It is not known since when the technique of training the smell has existed, but clinically it has been used for about a decade.

Rehabilitation basically consists of inhale smells, concentrating the mind, at least twice a day.

« It has to be every day, and they are short inhalations, more or less than 20 seconds, » explained Portillo Mazal.

Courtesy P. Portillo Mazal Patricia Portillo Mazal, a doctor at Hospital Italiano in Buenos Aires, has patients prepare their own kits.

In each exercise they are generally used four jars with different smells.

The four scents used by Hummel in his early studies were rose, lemon, clove and eucalyptus, but other substances can be used.

Portillo Mazal makes his patients prepare your own kits.

“I have two variants. ORna is with oilsThey can be made from fruits, flowers, peppermint, or things like lavender, thyme, or cloves. (The patients) put cotton or paper in a bottle and put about 40 drops, renewing every so often.

« The other option is a kit with things from the house: I tell my patients to prepare jars with machine coffee, powdered soap, oregano, or chopped chocolate, for example ”.

AbScentKelly recommends using dark jars so light does not affect scented oils. And he advises not to smell directly from dropper bottles because they limit the dispersion of odorants.

One of the centers that offers this type of rehabilitation in Spain is the Olfactory Training Unit of the Quirónsalud Sagrado Corazón Hospital in Seville.

« For two or three weeks, we subject the patients to different smells and different concentrations for 15 to 20 minutes, » Dr. Juan Manuel Maza, director of the Unit and a rhinologist and skull base surgeon at the Virgen Macarena University Hospital in Seville.

Gentileza Quiron SaludOne of the centers in Spain that offers rehabilitation is the Olfactory Training Unit of the Quirónsalud Sagrado Corazón Hospital in Seville.

“We can train discrimination. With repeated stimulation we get the patient to begin to identify and discriminate that smell ”.

« And after three weeks, patients can access odorants or formulations that they collect in different pharmacies and spend approximately three minutes a day. »

The importance of concentrating

A fundamental aspect of training is doing the exercises with great concentration.

« You have to be there for that minute and a half of the exercises, not thinking about what you have to do that day, » said Portillo Mazal.

Chrissi Kelly also recommends to evoke memories.

Courtesy Virginia MataVirginia Mata: « There are things you just take for granted until you no longer have them, like the scent of your favorite perfume or a pizza just delivered by a delivery man. »

« When you open your bottle with lemon oil, even if you don’t smell anything, close your eyes and remember all the details of when you smelled or ate a lemon. »

« AND you must be attentive to any olfactory message you perceive, even if it is not expected ”.

Even when she is not concentrating on her exercises, Virginia Mata often tries to « evoke a moment, some feeling. »

« For example, whenever it is raining I try to remember the smell of wet earth that immediately makes me remember those chaotic days of rain and traffic in Mexico City ”.

What are the results

« In general, about 60% of people who lose their sense of smell recover to some degree, » Thomas Hummel told BBC Mundo.

“And what our studies show convincingly is that with olfactory training the recovery rate doubles. That is to say, people recover more quickly and completely« .

In some cases « recovering » does not mean smelling exactly the same as before.

« Sometimes it’s like you’re in a strange country, there are smells that are like a new reality, » Kelly said.

Zara Patel, a professor of otolaryngology and skull base surgery at Stanford University in the United States, also investigated how effective smell therapy is.

« The main conclusion of my studies is that olfactory training has a significant benefit, » he told BBC Mundo.

« And when combined with irrigation with budesonide, a topical steroid, the training helps up to half of patients with olfactory dysfunction. »

“50% may not seem like a lot, but think that this is a breakthrough of the situation 10 years ago, when we literally had nothing to offer these patients« .

Dr. Maza said for his part that « between 45 to 70% of the patients » they attend recover.

Regarding the duration of training, Hummel speaks of a minimum period of between six and nine months.

In the case of Portillo Mazal, the Argentine specialist tells her patients: “Por at least let’s set a goal of six months before saying than this does not work« .

“I tell them that, hopefully, in two months they will have fleeting insights. Or they will suddenly smell the smell of bread, and they will look and there will be a bakery ”.

The wonder of the system olfactory

How do you explain that inhaling without smelling anything can help restore smell?

To understand why, the first thing to remember is that the olfactory system encompasses a cascade of events not only in the nose, but at the level of the brain.


« On the roof of the nose are the first cells that capture information, the so-called olfactory receptor neurons“Explained Portillo Mazal.

“The journey begins there, and from that cell the information goes to the brain, where the first stop is the olfactory bulb, a small but transmission and command center ”.

“From there the information continues to the rest of the brain. A first stop is the most primitive brain, that of emotions. Another is in the zone that allows to identify or discriminate one odor from another« .

« And it also goes to an area of long-term emotional memory, which is what makes you smell a chocolate and remember that first time with your grandmother ”.

The scientific basis of training

One of the keys that explain the effectiveness of rehabilitation is that the olfactory system has an extraordinary capacity for regeneration.

« A characteristic of the sense of smell that we do not see in other ways is its plasticity, » Dr. Hummel explained to BBC Mundo.

« Olfactory receptor neurons constantly regenerate« .

Along with these receptor neurons there are also two types of cells.

« The support cells they help neurons to function properly, ”said Dr. Portillo Mazal.

« And there are also the calls basal cells, which are totipotent like the famous stem cells, and which can be transformed into either of the other two, the support cell or neurons ”.

Zara Patel explained that “basal cells produce new olfactory receptor neurons throughout our lives. By repeatedly stimulating them with exposure to odorants, we are trying to tell them to ‘wake up.’

Courtesy JM Maza Dr. Juan Manuel Maza: “Smell is a sense that is also closely linked to taste, and part of the smells can be recognized with some chemoreceptors on the tongue.

Stimulation also produces changes in the brain.

« At one time it was believed that regeneration occurred only in neurons at the level of the roof of the nose, » said Portillo Mazal.

« But thanks to functional resonance it was seen that the brain also becomes more agile, manages to do more with the little information it receives, so the improvement is also due to plasticity at the level of the brain ”.

Maza reminds that in some cases it is even possible to resort to alternative ways of recovery.

« Smell is a sense that is also closely linked to taste, and some odors can be recognized with some chemoreceptors on the tongue that depend on other nerves that do not have to be damaged ”.

Portillo Mazal pointed out that smell training is to improve taste as well as smell, because taste is largely made up of smell.

“I frequently tell my patients that if they are doing the smell coffee exercise, for example, that they do it twice a day, once a day also drink some coffee savoring it« .

« When you exercise with something that you cannot eat (soap, for example) you can inhale through your mouth, hold it for a few seconds and exhale through your nose. »

The enigma of patients with covid-19

One of the big questions surrounding the new coronavirus is why some patients regain their sense of smell in less than two weeks, while others remain altered for months.

. Some people with COVID-19 regain their sense of smell in less than two weeks, but in others the recovery is much more complex.

Hummel raises a possible explanation.

« It has been shown that the new coronavirus affects support cells, » explained the expert.

“So it may be, although this is just a hypothesis, that in some people only these cells die, and the remains of those supporting cells cause inflammation that affects the receptor neurons. But when that acute inflammation subsides, the neurons still function. « 

« In other people, on the other hand, the inflammation is so strong that it also kills the receptor neurons olfactory, so recovery is much longer and more difficult ”.

In the case of the study carried out in 15 hospitals in Spain, “at the time of carrying out the study 45% of the patients had already recovered their smell spontaneously“Izquierdo Domínguez explained.

« But there are many patients that we are seeing in the consultation that have been four or five months and still do not recover their smell or have recovered it very partially ».

Do not give up

Four months after starting the olfactory training Saulo assures that his smell « is at 80% ».

Ana still perceives strange aromas and feels that she is “relearning each smell”.

Science Photo Library « Olfactory memory is a treasure and is sometimes undervalued, » said Virginia Mata.

Virginia admits feeling frustration, « because therapy is a slow process, but there are also good days when I perceive a different note in the air and that encourages me to continue. »

As for Chrissi Kelly, the founder of AbScent lost her nose again this year in the wake of covid-19. And although he made it back to a great extent, he still has parosmia.

The fundamental thing, for Portillo Mazal, is not to be discouraged.

“This can take a long time. We can’t promise everyone will get better, but I wouldn’t lower my arms« .

« You have to try, and this is difficult, to achieve the balance between starting rehabilitation but without the desire that you are going to improve, knowing that only maybe in a few months you will notice something. »