Understanding the Loss of Smell: A COVID-19 Symptom to Note
Written on
Chapter 1: Anosmia and COVID-19
The loss of smell, or anosmia, has emerged as a notable symptom among those diagnosed with COVID-19, even in cases where individuals do not exhibit severe illness.
According to a recent announcement from ENT UK, a professional body for ear, nose, and throat specialists in Britain, many COVID-19 patients have reported losing their ability to smell and taste. While this phenomenon has not been rigorously studied, numerous doctors from various countries have observed this symptom and suggest that it could serve as an important indicator of coronavirus infection.
Anosmia can be induced by numerous viruses, including various strains of coronaviruses and rhinoviruses, which are also responsible for the common cold. A partial loss of smell is termed hyposmia, and this condition can often coincide with a diminished sense of taste, known as dysgeusia.
Dr. Claire Hopkins, an ENT surgeon and professor at King’s College London, along with Dr. B. Nirmal Kumar, president of ENT UK, emphasized, “There is already compelling evidence from South Korea, China, and Italy indicating that a significant portion of patients with confirmed COVID-19 infections have developed anosmia or hyposmia.” Reports from Germany also reveal that over two-thirds of confirmed cases exhibited anosmia, while in South Korea, around 30% of patients with positive test results identified anosmia as their primary symptom, often in otherwise mild cases.
Dr. Clemens Wendtner, a professor of medicine at the Academic Teaching Hospital of Ludwig-Maximilians University in Munich, noted that many patients in Germany experiencing anosmia did not show any nasal congestion.
Anosmia can also arise from other medical conditions that block or disrupt the olfactory nerve cells located in the nasal cavity. While this symptom is typically not serious on its own and tends to resolve within weeks or months, it is important to note that the sense of smell naturally diminishes with age, similar to eyesight and other bodily functions.
High blood pressure, inadequate nutrition, seasonal allergies, Alzheimer’s disease, and certain medications can also lead to anosmia, according to Johns Hopkins Medicine. This raises questions about whether anosmia is directly caused by COVID-19, the respiratory illness linked to the SARS-CoV-2 virus, or if individuals exhibiting anosmia might have other underlying causes, as explained by Dr. Mahalia Desruisseaux, an associate professor of internal medicine at Yale University School of Medicine.
Given the known characteristics of other respiratory viruses, including coronaviruses, it is reasonable to consider that COVID-19 might be responsible for anosmia, Dr. Desruisseaux adds.
“I have seen four patients this week, all under 40, who are otherwise asymptomatic except for the recent onset of anosmia — typically, I see about one patient a month.”
A Growing and Confusing List of Symptoms
COVID-19 has presented a perplexing array of symptoms, which can be particularly frustrating for both healthcare professionals and individuals concerned about their health.
Traditionally, the three primary symptoms associated with COVID-19 have been fever, cough, and shortness of breath, which help differentiate it from a cold or flu. While these symptoms are prevalent in many severe cases, a significant number of individuals carry the virus with mild symptoms, or even none at all, thereby unknowingly transmitting the virus. Formal testing remains the only definitive method to confirm an infection, and limited testing capabilities have resulted in many potential cases going undiagnosed.
The emergence of anosmia represents yet another symptom to consider, particularly in patients who otherwise appear healthy.
Dr. Hopkins and Dr. Kumar noted, “Reports of a notable rise in patients experiencing anosmia without other symptoms are quickly accumulating.” They referenced medical discussion forums from various regions affected by COVID-19, highlighting that Iran has also reported a sudden spike in isolated anosmia cases. Dr. Hopkins remarked, “I have personally encountered four patients this week, all under 40 and asymptomatic apart from their recent anosmia — I typically see no more than one a month.”
This pattern suggests that these individuals may be undetected carriers contributing to the rapid transmission of COVID-19. Unfortunately, they often do not meet the current criteria for testing or self-isolation.
A physician in Italy noted that patients diagnosed with the virus frequently mention a spouse who has lost their sense of smell, indicating that the asymptomatic spouse may have transmitted the virus.
Dr. Desruisseaux commented, “With all these anecdotal reports, further investigation is essential to determine if anosmia is indeed related to COVID-19. However, it should not be dismissed as a potential symptom.”
What Actions Should Be Taken?
The American Academy of Otolaryngology, acknowledging the ENT UK findings, has provided clear guidance on what physicians should be attentive to. “Anecdotal evidence is rapidly accumulating from various locations around the globe that anosmia and dysgeusia are significant symptoms associated with the COVID-19 pandemic,” the organization stated. “In particular, anosmia has been observed in patients who ultimately test positive for the virus with no other symptoms. We advocate for these symptoms to be included in the screening tools for potential COVID-19 infection.”
Dr. Peter Gulick, an oncologist and infectious disease expert at Michigan State University’s College of Osteopathic Medicine, emphasized the need for caution regarding this new information, highlighting the necessity for increased COVID-19 testing to establish whether anosmia and dysgeusia are indeed indicative of the illness or merely coincidental.
Health authorities in the U.S. and other nations are urging anyone who suspects they may have COVID-19 to self-isolate. Dr. Gulick suggests that individuals who experience a loss of smell or taste, but show no other signs of illness, should also “keep an eye on other symptoms, such as fever, cough, or shortness of breath.”
[UPDATE]
Following the publication of this article and 24 hours post-interview, Dr. Desruisseaux reached out with an update: “We are increasingly observing cases of anosmia in younger individuals without other symptoms. Anyone experiencing anosmia, even in the absence of additional symptoms, should isolate until tested for SARS-CoV-2 to prevent transmission.”
The coronavirus situation is continuously evolving. To remain updated, refer to the U.S. Centers for Disease Control and Prevention and your local health department. If you are feeling overwhelmed, consider reaching out to the Crisis Text Line.
Chapter 2: Informative Videos on Anosmia and COVID-19
This video discusses new treatments for the loss of smell associated with COVID-19, providing insights into the experiences of patients and healthcare providers.
This video features a woman's experience of losing her taste and smell after contracting COVID-19, shedding light on the personal impact of this symptom.