Of the five senses, possibly that of smell is the most underrated. Seeing, listening, tasting or being able to appreciate a caress seems to us to be inalienable faculties; Knowing how to distinguish the aroma that emanates from a glass of Rioja from that emitted by a garbage can seems superfluous. It is not like this. Smell regulates such important functions as stimulating appetite, improving taste, warning of bad food and warning of dangers (the smell of smoke warns that there is a fire), as listed by Robert Shmerling , from Harvard University , in the United States. United.
However, as with vision , what we perceive through the nose can be distorted; or not reach us at all. The sense of smell is not free from false clues, from hallucinations that can play tricks on us. “Most of the time they do not imply any serious pathology,” says Dr. Miguel Fresnillo, from the IOM Institute of Otorhinolaryngology (Madrid). They are only very frequent symptoms derived from colds and viral infections. “They enter through the airways and the first thing they find is the nose. The olfactory nerve shares a nucleus with that of taste, in such a way that when you lose your sense of smell, you lose taste to a greater or lesser extent.”
It is not surprising, therefore, that loss of smell is one of the symptoms of the dreaded covid-19 . “These viruses, made up of very, very small particles, go to the roof of the nose. And that’s where they affect the sense-of-smell receptors, which are very delicate organs,” says Nirmal Kumar , president of ENTUK, a British group of specialists. in ear, nose and throat. This organization has counted in China and Italy a significant number of patients with coronavirus that has developed this decrease; in Germany, in two out of three cases; in South Korea 30% of people with a positive diagnosis have experienced it. But don’t assume that you are infected with SARS-CoV-2 if you have this symptom.
Losing your sense of smell, even if not completely, is more common than it seems. “Smell disorders affect 19% of the population over the age of 20 [much more than those with symptoms of SARS-CoV-2 infection] and 25% of the population over the age of 53. If its loss is considered just from aging , one in eight people between 53 and 91 will be affected over a period of five years, “says Eric Holbrook , a senior at Harvard. These are the most common cases.
From not smelling anything to imagining smells
The impossibility of qualitatively detecting olfactory sensations, that is, the absence of olfactory function, is called anosmia . “The most common causes of prolonged loss of smell occur as a result of upper respiratory tract infection, head injury, chronic sinus disease and aging,” adds Holbrook. A very common origin is rhinitis due to allergy to pollen (and, to a lesser extent, to mites), according to a study carried out by researchers at the Badalona Municipal Hospital and the Barcelona Clinic in 2008.
The other alteration of the sense of smell is hyposmia, by which people only detect some odors. “It would be a less aggressive form than anosmia,” describes Miguel Fresnillo. It is because the nucleus of olfaction is not right, but there is part that is active. “Its possible causes are nasal or paranasal disease, radiation therapy and exposure to toxins such as cigarette smoke, among others. It has been shown that an increase in age over 65 also causes this condition,” says a medical article. Chileans.
“Exposure to tobacco smoke can have an influence, of course,” confirms Fresnillo. “One of the places it affects is the nose. We are all afraid of the injuries it produces to the lung, but little by little it is making the olfactory nerve not work as well as it should. One of the first things they refer to the people who have quit smoking is beginning to perceive odors not previously perceived. ” It can also deteriorate with age. “Logically there is neuronal wear and tear; the nasal mucosa is atrophying, and the capacities are diminished,” he explains.
One of the most unique effects of hyposmia is that the perceived odors are often unpleasant. “When the olfactory pathways are altered, these what they translate are those distortions; like when a muscle begins to react and a cramp is perceived , which is the way of recanalization of that nerve. What you perceive are intense smells, not the nuances” Fresnillo says. It’s a good sign: “Olfaction starts to recover that way,” says the otorrino.
Other manifestations are parosmia and phantosmia. They can reveal sinusitis , but they are also caused by major ailments, such as brain tumors, neurological and psychiatric disorders, or epilepsy. In the first, “the smells smell dramatically different from what was remembered”; in the second, “you smell an odor that is not present,” defines Holbrook. “Conditions such as Alzheimer’s or Parkinson’s disease may be associated with loss of smell,” adds the specialist.
As it disappears, the smell can return
The good news is that the olfactory system’s ability to repair itself allows some patients to recover their sense of smell naturally, when their loss is related to infections or head injury. The bad: The process can take over a year and be so gradual that people have a hard time recognizing the change. “The first thing to do is rule out the existence of any major injury; once you verify that there is not, proceed with anti-inflammatory treatment ,with corticosteroids, thinking that nerve is inflamed and going to help you a little, “says Fresnillo.” In cases where loss of smell results from sinus disease, oral and topical steroids often provide relief. Sometimes surgery is required to reduce odor obstruction to sensory nerve cells, “says Holbrook.
The long road to recovery can despair those who suffer from it. “The symptoms remain for months; that prevents us from knowing, for example, if what you are cooking is burning or not … forget about tasting a good wine … They are banal problems, but they are indeed very uncomfortable,” says Fresnillo. In other words: one ends up to the nose.