MANILA, Philippines—Throughout the COVID-19 pandemic, awareness and studies on the loss of sense of smell has increased as many patients infected by SARS-CoV-2 exhibited a symptom also known as anosmia.
This has been talked about even before the pandemic, but gained traction again after actress Andrea Brillantes announced to the world she had lost her sense of smell.
Last month, Brillantes opened up about having no sense of smell. In a vlog with comedian Vice Ganda, Brillantes shared she was diagnosed with congenital anosmia, which, she lamented, prevents her from having a “complete life experience.”
“Do you know that I do not have a sense of smell? I was born without the ability to smell,” the young actress said.
“I cried over it because I was told that it has no cure. Of course, it’s sad because my life experience is not complete. I cannot smell the celebrities I meet,” she added.
READ: Andrea Brillantes bares having no sense of smell: ‘Di complete ‘yung life experience ko’
According to the National Organization for Rare Disorders (NORD), congenital anosmia is a “condition in which people are born with a lifelong inability to smell.”
In a previous interview last year with broadcast journalist Karen Davila, Brillantes explained that while she cannot smell, she sometimes relies on sensation or how certain products—such as rubbing alcohol and perfume—feel after applying them to her skin.
READ: Andrea Brillantes can’t smell because she’s got congenital anosmia
While some people knew about loss of sense of smell as a condition linked with COVID-19, Brillantes’ statements about her condition may have led to a broader understanding of anosmia—including its various types and causes.
‘Anosmia’: What is it?
According to the US-based Cleveland Clinic, anosmia, or the condition that affects a person’s ability to detect odors, is a common side effect of various conditions such as colds, sinus infections, and allergies.
While the temporary loss of sense of smell can affect people of all ages, long-lasting anosmia is commonly observed among adults over the age of 50.
Aside from being a side effect of many common conditions, various studies have also identified anosmia as a common symptom of COVID-19.
Based on a 2021 Adult National Health Interview Survey published June 02, 2023 in The Laryngoscope, anosmia affects 60 percent of the adult population who had been diagnosed with COVID-19.
A separate study published last year in The BMJ also found that around 5 percent of COVID-19 patients report persistent anosmia months after infection.
Early in the pandemic, when little was still known about COVID-19, the connection between the disease and loss of smell among COVID-19 patients was also unexplained—making anosmia a “mysterious” symptom of the disease.
However, recent studies are finally making progress in yielding answers as to how SARS-CoV-2 leads to loss of smell in some patients. Multiple potential treatments for anosmia were also undergoing clinical trials.
READ: The mystery of anosmia, loss of smell, and its COVID links
Different types of anosmia
Congenital anosmia, NORD explained, may occur as an isolated abnormality or with no additional symptoms. This type of congenital anosmia is usually sporadic or occurs occasionally, although some familial cases have been reported.
“In most cases of isolated congenital anosmia, the genetic cause is unknown. Unfortunately, there is currently no cure or treatment for congenital anosmia,” the organization said.
Aside from congenital anosmia, there are two other types of this condition.
One of those is called functional anosmia, which, according to the US National Institute of Health, refers to a significantly reduced ability to smell, “although some smell sensations can be present.”
This means that a person diagnosed with functional anosmia can detect odors occasionally, but has no practical day-to-day sense of smell.
Another specific type of anosmia is called idiopathic anosmia. While anosmia is a result of conditions such as upper respiratory infections, nasal or sinus disease, and other less common causes, up to 30 percent of cases of anosmia are idiopathic or display no known origin.
Fifth Sense, a UK-based charity for people affected by smell and taste disorders, explained that idiopathic anosmia is diagnosed in patients “in whom after extensive testing no cause for the loss of sense of smell is found.”
According to Cleveland Clinic, the duration of having no sense of smell depends on its underlying cause. Usually, a person’s sense of smell returns once treatment is complete—unless it is congenital.
For COVID-19 patients who have lost their sense of smell, the US-based clinic clarified that current research has determined that coronavirus may cause smell dysfunction, but it doesn’t cause permanent anosmia.
“People who have anosmia as a COVID-19 side effect usually regain their sense of smell in approximately two to three weeks. This is an estimate; recovery times can vary,” said Cleveland Clinic.
Many causes of loss of smell
Several conditions cause temporary or lifelong loss of smell. For instance, temporary irritation or congestion inside the nose may be caused by conditions such as:
- acute sinusitis
- chronic sinusitis
- common cold
- COVID-19
- hay fever (or allergic rhinitis)
- influenza (flu)
- nonallergic rhinitis
- smoking
Yale Medicine noted that conditions can cause an obstruction that blocks the flow of air through the nose. Other conditions, meanwhile, can lead to damage to brain nerves and may damage or deteriorate an area of the brain that detects smell.
“In addition, the olfactory pathways, which send messages between the nasal passages and the brain, can become impaired from age and from certain medications. Also, certain medical conditions can dull or diminish the sense of smell,” Yale Medicine explained.
Since anosmia is a symptom or effect of various health-related conditions, Cleveland Clinic explained that it cannot always be prevented. However, there are several things people can do to reduce the risk of losing their sense of smell, including:
- avoiding toxic chemicals and environments
- not smoking
- wearing protective gear when playing contact sports, since anosmia can be caused by brain injuries
TSB
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