We have all become familiar with the loss of smell since the COVID-19 pandemic, becoming one of the main symptoms of SARS-CoV-2 infection. However, the loss of smell has existed since before the pandemic and due to numerous reasons why a person can lose this sense, more important in our day to day than in many cases we consider.
And it is that olfactory dysfunction, that is, a reduction in the adequate capacity to perceive odors, has profound effects on the quality of life of those who suffer from it.
“It affects both the ability to experience pleasant odors and the ability to detect potentially harmful odors and substances. This dysfunction can range from a slight decrease in the sense of smell (hyposmia) to a complete loss of it (anosmia),” specifies doctor Valery Núñez, from the Otorhinolaryngology service of the Hospital Universitari General de Catalunya.
In fact, he finds himself in the office with patients distressed by hyposmia and their inability to taste the flavors of food. “It’s a life-altering experience and most people can’t understand the impact it has on our day-to-day lives.”
And it is that, although we do not believe it, Dr. Núñez says that the main cause, by far, and the least recognized of the loss of smell is advancing age: “While only 1 or 2 percent of young people affected, a quarter of those over 55 and nearly two-thirds of those over 80 have a diminished sense of smell.”
But unlike the loss of vision or hearing, which is usually evident to others, the loss of olfactory sensitivity with age usually goes unnoticed because it occurs gradually, maintains this expert from the Otorhinolaryngology service.
The result can be a decreased interest in food, as well as a gradual loss of weight or a tendency to over-season foods with salt or sugar, which can ultimately impair alertness, control of high blood pressure or diabetes, common problems in older people.
Possible causes would also include viral infections, such as colds and flu, not just COVID-19, while also including disorders of the nose, such as polyps, or sinuses, in addition to injuries to the nose or head, medications such as blood pressure medications, antibiotics, cholesterol lowering medications, antidepressants, and cancer chemotherapy.
This specialist also points out, among other possible causes, radiation therapy to the head and neck, exposure to toxins such as formaldehyde and pesticides, as well as smoking and alcohol abuse. “There are also recognized as possible causes of loss of smell some diseases of the thyroid, kidneys, liver or pancreas, and neurological disorders such as Parkinson’s disease, Lewy body disease, multiple sclerosis and various types dementia,” he continues.
What’s more, Dr. Valery Núñez points out that half of people with diabetes have a diminished sense of smell and taste, and 90 percent of those with Alzheimer’s disease have their olfactory capacity altered.
With this, this specialist from the Hospital Universitari General de Catalunya points out that, depending on the cause of the smell disorder, the therapeutic possibilities include treatment with nasal decongestants, antihistamines or antibiotics, but surgery to remove nasal polyps, the use of a nasal saline solution, correction of hormonal or nutritional deficiencies, and smoking cessation.
“Especially difficult are those derived from head injuries, whether mild or severe, which alter the function of the body’s olfactory receptors, that is, the olfactory nerve cells that are located outside the brain. These cells pick up odor molecules at the top of the nose and transmit odor messages to the olfactory bulb of the brain,” he adds.
In fact, this otolaryngologist warns about the fact that a blow to the head can injure or tear the olfactory nerves: “Damaged olfactory nerve cells can regenerate, but they do not always reconnect correctly in the brain.”
Regarding the treatment for hyposmia due to COVID-19, Dr. Núñez maintains that there is no consensus among experts; however, he does affirm that the most recommended is usually olfactory therapy, as well as nasal corticosteroids and topical vitamin A. Ultimately, and in the absence of olfactory ability, this physician recommends having smoke detectors in homes, a natural gas or propane detector, lest a leak go undetected and cause an explosion.
“Perishable foods should be dated and kept refrigerated, and thrown away when they expire. It may be helpful for a person with normal olfactory function to check these foods before they are eaten by someone with impaired sense of smell. Make sure all cleaning and gardening products are properly labeled and stored separately from food. When cooking or baking, periodically check that nothing is burning and set a timer to go off when the food is ready,” he concludes.
