“Is the Loss of Smell and Taste a Sure Sign of COVID-19?”

Joseph R. Anticaglia MD
Medial Advisory Board

Over the past several months, problems with a person’s ability to smell or taste has been in the news for different reasons. Increasing evidence suggest that a loss of smell or taste is an early warning sign of Covid-19.

“The one symptom …that really differentiates flu from COVID is loss of taste or smell” US Surgeon General Dr. Jerome M. Adams said on NPR’s All Things Considered. “If you get that symptom, then you need to be reaching out to your health provider right away and going in and getting a COVID test.”

I agree with the Surgeon General’s recommendation to get a COVID-19 test. However, it’s been known for many years that there are other causes for loss of taste and smell.

Decades before COVID-19 became part of our vocabulary; clinicians were challenged to figure out why a person had difficulty with his sense of taste or smell. Surprisingly, for many, problems with the sense of smell play a major role with your ability to taste foods and enjoy drinks.

Smell and Taste

Some Causes

Many conditions can cause a loss of smell or taste. Could the loss be caused by nasal polyps, a deviated septum or tumor within the nose? Or might there be damage to the olfactory (smell) nerve due to a bacterial or viral infection, airborne toxin or vitamin deficiency? Could the central nervous system be involved because of a tumor or conditions such as Parkinson Disease? Or might the blockage of a stuffy nose after a common cold or the virus itself, interfere with the sense of smell and taste?

When I was a kid, occasionally, I would ask my Mother to make my least favorite dish when I had the common cold. At mealtime she was happy because the food was “good for you” and I was happy because I couldn’t smell or taste it. Don’t get me wrong, my Mom was a great cook, but as far as I could tell, she didn’t know or let on why I would request my least favorite food for dinner when I had a cold as a child.

A Simple Test

Try this simple test to find out how the sense of smell plays an important role in our appreciation of taste and flavor. Take a sip of coffee or eat a piece of chocolate or have a teaspoon of ice cream or jam. Notice how it tastes. Next, rinse your mouth with water. Now pinch the lower two//thirds of the nose (the area below the bony part of the nose) and drink or taste the same food or drink you did just a few minutes before. Notice the change?

Studies

A report in Mayo Clinic Proceedings in August, 2020 noted there’s a high prevalence of smell and taste disorders “among patients infected with COVID-19. Routine screening

for these conditions could contribute to improved case detection in the ongoing COVID-19 pandemic.”

According to a study published in JAMA last year, at 4 weeks from the onset of smell or taste abnormality, approximately 49% of the subjects reported complete resolution of their smell or taste symptoms. About 41% reported an improvement in the severity of their complaints and ten percent said their symptoms were unchanged or worse.

Takeaways

What sets smell or taste impairment due to COVID-19 apart from other viruses is: the onset is sudden. People with COVID can breathe normally (no stuffy or blocked nose (e. g. from a cold), the clinical course is milder and the loss of taste is more significant.

We’re in a period of increased transmissibility because of the mutation of SARS-CoV-2 virus. The public health measures of wearing a mask, social distancing, washing your hands frequently and avoiding crowds are especially important at this time. If you experience a sudden loss of smell or taste, get the COVID test as soon as you can

Glossary

Terms associated with smell and taste: Anosmia or hyposmia or dysosmia or olfactory dysfunction or olfaction disorder or smell dysfunction or ageusia or hypogeusia or dysgeusia or taste dysfunction or gustatory dysfunction. OGD — Olfactory and gustatory dysfunction.

Reference

  1. Agyeman A. A, et al; Smell and Taste Dysfunction in Patients with COVID-19; Mayo Clin Proc. May 5, 2020
  2. R I Henkin et al; Hypogeusia, dysgeusia, hyposmia, and dysosmia following influenza-like infection; Ann Otol Rhinol Laryngol, Sept-Oct, 1975
  3. Paolo Boscolo-Rizzo, MD et al; Evolution of Altered Sense of Smell or Taste in Patients With Mildly Symptomatic COVID-19; JAMA Otolaryngology — Head and Neck Surgery, July 2,2020
  4. Joseph R. Anticaglia, MD; Anosmia: I Can’t Smell That; Doctor’s Column, HC Smart, 2016
  5. Joseph R. Anticaglia, MD; Fifteen Facts About the Olfactory Nerve — The Sense of Smell; Doctor’s Column, 2016
  6. Joseph R. Anticaglia, MD; Taste and Smell — The Olfactory Nerve and the Five senses; Doctor’s Column, HC Smart, 2016

This article is intended solely as a learning experience. Please consult your physician for diagnostic and treatment options.