APR 17, 2020 6:45 AM PDT

Allergies or Coronavirus? The Nose Knows

WRITTEN BY: Carmen Leitch

The coronavirus that causes COVID-19 has been responsible for thousands of deaths worldwide, and we've learned that it can cause a wide range of health problems. Data from countries like South Korea, where testing has been widespread, has shown just how varied the infection can be in different people. Many show no symptoms at all, others get a cough, while a smaller proportion has a serious respiratory infection that can result in death. Because it's a respiratory illness, it shares symptoms with many other common illnesses, including seasonal allergies. So how can people tell the difference? As noted last month, one symptom that has been identified in SARS-CoV-2-positive individuals that have no other problems has been the loss of smell, and it's being used more often to identify suspected cases. So if a person can't smell anything but doesn't have nasal congestion, it may indicate the presence of the virus.

"COVID-19 is not associated with the symptoms that are typically associated with a viral cold such as nasal blockage or mucus production," said Ahmad Sedaghat, an associate professor at the University of Cincinnati College of Medicine's Department of Otolaryngology-Head and Neck Surgery.

After reviewing nineteen studies describing the illness caused by the virus, Sedaghat came to the conclusion that the loss of smell, also called anosmia, of a patient, is "a highly specific indicator of COVID-19." His findings have been reported in Laryngoscope Investigative Otolaryngology.

"This distinction is also why it is fairly easy to distinguish COVID-19 from seasonal allergies. COVID-19 is associated with a fairly unique combination of nasal symptoms: a sudden loss of one's sense of smell, also known as 'anosmia,' without nasal obstruction," added Sedaghat. "The occurrence of sudden onset anosmia without nasal obstruction is highly predictive of COVID-19 and should trigger the individual to immediately self-quarantine with presumptive COVID-19."

COVID-19 is caused by a virus that incubates in the body before it causes symptoms, so it may take two to fourteen days after exposure to the virus for symptoms to appear. These symptoms include fever, cough, and shortness of breath. If breathing trouble gets so bad that a person has constant chest pain or a hard time standing up, it's time to seek medical attention, according to the Centers for Disease Control and Prevention.

Most people that get sick will recover. We still don't know how long the loss of smell persists in every person, however. It is assumed that in most people, the sense will return a few days or weeks after the infection resolves. It may take longer for some, however.

SARS-CoV-2 can spread if it's being produced in the lining of the nose. It can then be released via mucus. "Nasal virus production is at very high levels and tends to occur early in the disease process while patients are still asymptomatic or having very mild symptoms," Sedaghat said. "When someone sneezes, this mucus, which contains the virus, is aerosolized outwards. Similarly, if someone wipes their nose and then touches surfaces without washing their hands first, that could lead to [the] spread of COVID-19."

Transmission electron micrograph of SARS-CoV-2 virus particles, isolated from a patient. Image captured and color-enhanced at the NIAID Integrated Research Facility (IRF) in Fort Detrick, Maryland. / Credit: NIAID

This knowledge may inform people that feel fine and have no idea they may be infected.

"A sudden loss of one's sense of smell wouldn't trigger most people to think they have COVID-19," said Sedaghat. "These individuals could continue business as usual and spread the disease as a carrier. The guidelines for when to formally test for COVID-19 remain fluid in the setting of limited tests. But if someone experiences anosmia without nasal obstruction, aside from quarantining, it would not be unreasonable to reach out to one's primary care physician about getting tested."

Sources: AAAS/Eurekalert! via University of Cincinnati, Laryngoscope Investigative Otolaryngology

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
DEC 22, 2020
Health & Medicine
Cannabis Use May Help People on an Opioid Detox Program Stay on Track
DEC 22, 2020
Cannabis Use May Help People on an Opioid Detox Program Stay on Track
New research suggests that cannabis use by people being treated for opioid addiction might improve outcomes and reduce t ...
DEC 23, 2020
Health & Medicine
Holiday Cheer: Americans Swap Alcohol for Cannabis this Christmas
DEC 23, 2020
Holiday Cheer: Americans Swap Alcohol for Cannabis this Christmas
Cannabis users polled by Glasshouse Group — a California-based cannabis and hemp company, which runs several dispe ...
DEC 30, 2020
Drug Discovery & Development
Llama Antibody Prevents Infection by COVID-19
DEC 30, 2020
Llama Antibody Prevents Infection by COVID-19
There's more to llamas than being livestock and hilarious companion animals. They also harbor an immune system capab ...
JAN 07, 2021
Cardiology
Climbing Some Stairs is a Good Way to Check Heart Health
JAN 07, 2021
Climbing Some Stairs is a Good Way to Check Heart Health
If you can climb four flights in under a minute, your heart is probably in good shape, according to new work presented a ...
JAN 13, 2021
Immunology
Antibodies Gain the Upper Hand Against Sly Tumors
JAN 13, 2021
Antibodies Gain the Upper Hand Against Sly Tumors
Tumors use ingenious approaches to stay just out of reach of immune cells on patrol and avoid detection. Indeed, cancer ...
JAN 19, 2021
Immunology
How Breastfeeding improves Infants Immunity?
JAN 19, 2021
How Breastfeeding improves Infants Immunity?
Breastfeeding benefits are well known for ages, and it has many positive impacts on infant's lives that continue wit ...
Loading Comments...