As the COVID-19 virus continues to spread, there are increasing numbers of people who report prolonged loss of smell after contracting the virus.
One study found that as many as 77 percent of those who had COVID-19 were estimated to have some loss of smell.
“Other viral illnesses have been known to cause a loss of smell, but it was uncommon before the COVID-19 pandemic,” said Dr. Alexander Ramirez, medical director for the Otolaryngology Clinical Program for Intermountain Healthcare, “The SARS-CV-2 virus binds the ACE receptors which we see in abundance in the olfactory area of the nasal cavity, so it is not surprising that we are seeing it more frequently with COVID-19.”
In most patients the loss of smell is temporary, but for others it can be prolonged, taking months or even years to fully recover. In fact, Dr. Ramirez says it is a common problem he sees in Long COVID patients.
“That lack of smell also causes dysgeusia, which is a disruption with their ability to taste which is largely regulated by smell,” said Dr. Ramirez. “As a result, patients will often lose their desire to eat, drop significant amounts of weight, and lose the joy of smells in life. In addition, there is the risk of fires and not smelly things that might be burning.”
Dr. Ramirez and other physicians are recommending a treatment called Olfactory training, also called smell training, to help their patients recover that sense of smell. It has been shown to be beneficial for patients with anosmia caused by other viruses, so it has been applied to COVID patients.
What is smell training?
Smell training is often called “physical therapy” for your nose and involves sniffing the same strong and very distinctive four scents every day for 20 seconds on each scent.
It’s easy, it’s safe, and doctors recommend it, but it does take time, consistency and dedication.
How does it work?
Cranial Nerve 1 has a unique ability to regenerate and the part of the brain that controls smell has a significant amount of neuroplasticity. As a result, undergoing the smell training can help it re-learn and recover.
The most studied method, with good evidence for success, is to use four scents: 1. Rose, 2. Eucalyptus, 3. Lemon, and 4. Cloves. Doctors suggest sniffing for 20 seconds each, twice a day for 3- 6 months, although it may take up to a year.
Experts suggest putting the four scents in a location easy to access and take short sniffs for about 20 seconds for each scent, twice a day.
You can purchase smell retraining kits online or you can make them yourself by putting the essential oils into an open container with a lid, such as a jar. You do not want to put them into your nose but put your nose 1-2 inches from the opening of the container and sniff. Dr. Ramirez suggests having someone without anosmia try it to be sure they can easily smell the scents when it is a couple of inches below the nose.
If these specific scents are not available, Dr. Ramirez recommends selecting four scents that are familiar to you that maybe evoke specific memories. This could include a favorite cologne or perfume, certain spices, essential oils, or even items that smell bad like spoiled milk or an onion.
Dr. Ramirez also tells patients it’s not just the act of sniffing that’s important, patients also need to focus and visualize what they are smelling.
“Essentially it’s retraining your nose and your brain to recognize those smells,” said Dr. Ramirez.
“It’s combining the stimulation of the isolated scent with the visual imagery that train those nerves to come back to life or remember how they are supposed to be working.”
How long does it take?
Patients have to be consistent, but even then, it could take a few months to a year.
Dr. Ramirez also reminds patients that smell training is perfectly safe to try, but anyone experiencing prolonged smell loss after recovering from COVID-19 should first make an appointment with an ear, nose and throat specialist to rule out other potential causes, such as allergies or polyps. Those ailments might be affecting your sense of smell but would need treatments other than olfactory training.