Losing your sense of smell can be an early hallmark of a COVID-19 infection—and a new study has identified why, for some people, this symptom can last long after the initial infection as a sign of Long COVID.
“SARS-CoV-2 causes profound changes in the sense of smell, including total smell loss. Although these alterations are often transient, many patients with COVID-19 exhibit olfactory dysfunction that lasts months to years,” says the new study, published December 21 in Science Translational Journal.
The researchers found that a very specific kind of inflammation may be to blame for this condition, also called anosmia. Read on to see what exactly they discovered and how you can stay safe.
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What the Scientists Found
The scientists “analyzed biopsies of olfactory mucosa collected from COVID-19 patients with persistent smell loss using single cell RNA-sequencing and immunohistochemistry.”
In layman’s terms, they gathered nose tissue samples, 24 in fact, from patients who have long-term smell loss from COVID, and compared them to those who never got COVID but lost their sense of smell (and those who had COVID but never lost their sense of smell).
The “biopsies from hyposmic individuals exhibited fewer olfactory sensory neurons and altered immune cell populations including T cells producing”…altered immune cell populations in olfactory epithelia contribute to long-term smell loss after COVID-19.”
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The Findings are “Striking”
“The findings appeared pretty striking to us — there really are some very obvious differences,” said Dr. Bradley Goldstein, a Duke neuroscientist who led the research, according to the Seattle Times.
He summed it up as a sort of inflammation. “I’m not talking about sort of this rip-roaring, severe nasal inflammation where you’re super congested, blowing your nose and feeling like you’re sick,” he said. “It’s more at a local microscopic level.”
This new research may lead researchers to finding a cure.
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Losing Your Sense of Smell After Viral Infection Is Not Uncommon
Even before COVID, people with viral infections were losing their sense of smell. There are several different mechanisms by which viruses can cause a loss of smell.
One way is through direct infection of the cells that are responsible for detecting and transmitting smells, which are called olfactory neurons. These neurons are located in a small patch of tissue in the upper part of the nasal cavity called the olfactory epithelium. Olfactory neurons are sensitive to infection by viruses, and if they are damaged or destroyed, it can lead to a loss of smell.
Another way that viruses can cause a loss of smell is through inflammation of the nasal passages or sinuses. As the study shows, many viruses, including the SARS-CoV-2 virus that causes COVID-19, can cause inflammation of the nasal passages and sinuses as part of the body’s immune response to the infection. This inflammation can obstruct the flow of air and mucus through the nasal passages and make it difficult for smells to reach the olfactory neurons.
It’s also possible for a loss of smell to be a symptom of a more general illness or condition that is not directly caused by a virus, such as allergies, nasal polyps, or certain medications. In these cases, the underlying condition may need to be treated in order to restore the sense of smell.
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Many COVID Symptoms Can Last for Years, Known as “Long COVID”
Long COVID, also known as post-acute COVID-19 syndrome or “long haul” COVID-19, refers to the persistent symptoms that some people experience after recovering from COVID-19, the illness caused by the SARS-CoV-2 virus.
These symptoms can range from mild to severe and can last for several weeks or months after the initial infection. The most common symptoms of long COVID include:
Fatigue or tiredness
Shortness of breath
Chest pain or discomfort
Headache
Muscle or joint pain
Difficulty sleeping
Loss of taste or smell
Brain fog or difficulty concentrating
Depression or anxiety
Heart palpitations
Other possible symptoms of long COVID include fever, cough, sore throat, and loss of appetite.
Some people may also experience difficulty returning to their normal level of physical or mental function or may have ongoing symptoms that disrupt their daily activities.
It’s important to note that the symptoms of long COVID can vary widely from person to person, and not everyone who has had COVID-19 will experience long-term symptoms.
If you’re experiencing persistent symptoms after recovering from COVID-19, it’s important to talk to your healthcare provider for further evaluation and treatment.
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How to Stay Safe Out There
Winter travel and China’s lifting of its “Zero COVID” policy is resutling in a rise of COVID cases worldwide. There are several steps that you can take to protect yourself and others from COVID-19:
Wear a mask: Wearing a mask or face covering can help to reduce the spread of the virus, especially when combined with other preventive measures. It is important to use a mask that covers your nose and mouth and to wear it correctly, making sure that it fits snugly against your face.
Practice good hygiene: Wash your hands frequently with soap and water for at least 20 seconds, or use an alcohol-based hand sanitizer. Avoid touching your face, especially your eyes, nose, and mouth.
Keep your distance: Maintain a distance of at least 6 feet from others whenever possible.
Avoid large gatherings: Limit your contact with others as much as possible, especially in crowded or enclosed spaces.
Stay home if you are sick: If you are experiencing symptoms of COVID-19 or have been exposed to someone with the virus, stay home and self-isolate to prevent spreading the infection to others.
Get vaccinated: Getting vaccinated can help to protect you and those around you from COVID-19. Vaccines are effective at reducing the risk of severe illness and death from the virus and can help to slow the spread of the virus in the community.
By following these steps and staying informed about the latest recommendations and guidance, you can help to protect yourself and others from COVID-19.
