Can you lose your taste and smell from a cold

CNN  — 

Loss of smell and taste is more severe in Covid-19 patients than in patients with common colds and that could be due to the effect the coronavirus has on the brain and nervous system, British researchers reported on Wednesday.

Loss of smell and taste is a symptom of Covid-19, but patients infected with coronaviruses that cause the common cold can also lose taste and smell because of congestion. The new research, described in a letter to the editor published in the journal Rhinology, suggests that loss of taste and smell in Covid-19 patients isn’t simply due to congestion in the nose.

“We know that Covid-19 behaves differently to other respiratory viruses, for example by causing the body’s immune system to over-react, known as a cytokine storm, and by affecting the nervous system,” Carl Philpott, of the University of East Anglia’s Norwich Medical School who was involved in the research, said in a news release on Wednesday.

“So we suspected that patterns of smell loss would differ between the two groups,” he said.

Philpott and his colleagues studied smell and taste function in 10 Covid-19 patients, 10 acute cold patients and 10 healthy people who served as a control group.

The researchers not only found that the smell and taste function of Covid-19 patients was significantly worse than in both the cold patients and the healthy individuals – but also the ability to detect sweet and bitter tastes was particularly impaired in Covid-19 patients.

“It is particularly interesting that Covid-19 seems to particularly affect sweet and bitter taste receptors, because these are known to play an important role in innate immunity,” Philpott said in the release.

Philpott called for additional research to explore the relationship between the virus and these taste receptors.

“It was this loss of true taste which seemed to be present in the Covid-19 patients compared to those with a cold,” he said in the release.

The researchers believe that loss of taste in Covid-19 patients isn’t just more severe, but is caused by a different mechanism in the olfactory system, which is responsible for the body’s sense of smell. The researchers say their findings indicate that Covid-19 patients are experiencing a direct loss of the ability to taste, rather than an indirect loss of taste because the sense of smell is impaired.

Covid-19 can produce increased inflammation throughout the body. The researchers suggest that this inflammation can damage taste receptors. They say it is also possible that Covid-19 can affect a part of the brain stem connected to the sense of taste.

Both the Covid-19 and cold patient groups in the study reported improvement in their sense of taste and smell over time, although only 30% of Covid-19 patients reported complete recovery.

The researchers say it is likely that a portion of the Covid-19 patients will experience persistent loss of taste after they clear the virus.

The research had some limitations, including the small study size. More research is needed to determine whether similar findings would emerge among a larger group of Covid-19 and cold patients.

Yet overall, Philpott and colleagues say smell and taste tests can discriminate between Covid-19 and cold patients, which means these tests could potentially be an additional screening tool for those with the novel coronavirus.

The US Centers for Disease Control and Prevention includes a “new loss of taste or smell” on its list of Covid-19 symptoms to watch for.

“What’s called anosmia, which basically means loss of smell, seems to be a symptom that a number of patients developed,” CNN Chief Medical Correspondent Dr. Sanjay Gupta told CNN anchor Alisyn Camerota on “New Day” in July.

That symptom appears to be more prevalent in mild or moderate cases of Covid-19, and tends to appear at the beginning of the illness. It may even be one of the first signs that you are sick.

CNN’s Sandee LaMotte contributed to this report.

Overview

What is anosmia?

Anosmia is the loss of sense of smell. This condition affects your ability to detect odors.

What is the difference between ageusia and anosmia?

While anosmia refers to a total loss of smell, ageusia refers to a complete loss of taste. These two conditions sometimes occur together because sense of smell and sense of taste are closely related.

Are there other smell disorders?

Yes. In addition to anosmia, people can also develop phantosmia (smelling things that aren’t there), parosmia (a distorted sense of smell) and hyposmia (a reduced sense of smell).

Who does anosmia affect?

Temporary anosmia can affect people of all ages. But a long-lasting loss of sense of smell is more common among adults over the age of 50. In rare cases, people have congenital anosmia. In other words, they were born with the condition. Congenital anosmia affects roughly one in 10,000 people.

How common is anosmia?

Anosmia is a common side effect of many conditions, including colds, sinus infections and allergies. Most of the time, symptoms are temporary and resolve themselves in a short amount of time. Anosmia is also a common symptom of COVID-19.

Is anosmia dangerous?

While anosmia itself usually isn’t dangerous, it can be related to many concerning health issues. Additionally, it can reduce your ability to detect the smell of smoke, gas leaks or spoiled food. As a result, people with anosmia should take extra steps to ensure that their environment is safe. Change the batteries in your smoke detectors frequently and read food expiration dates carefully.

Diagnosis and Tests

How is anosmia diagnosed?

Anosmia is usually diagnosed by an ear, nose and throat specialist (ENT). They’ll ask you about your symptoms, examine your nose and run tests to determine the extent of your loss of smell. In some cases, a CT (computed tomography) scan may be necessary to help your provider see what’s going on inside your body.

Management and Treatment

How is anosmia treated?

In most cases, treating the underlying condition can help restore your sense of smell. For example, if you have sinusitis, then antibiotics can help clear up the infection. If certain medications are affecting your sense of smell, then switching meds may help ease your anosmia symptoms. If you have nasal polyps or another type of blockage, surgery may be necessary. Your healthcare provider can help determine any underlying conditions and recommend appropriate treatment.

Can anosmia be cured?

It depends on the type of anosmia you have. There is currently no known cure for congenital anosmia. In most cases, however, anosmia goes away on its own. Generally, once the underlying problem is treated, your sense of smell is restored.

Prevention

Can anosmia be prevented?

Because anosmia is a symptom of many health-related conditions, it can’t always be prevented. However, there are certain things you can do to reduce your risk:

• Avoid toxic chemicals and environments.
• Don’t smoke.
• Wear protective gear when playing contact sports, since anosmia can be caused by brain injuries.

Can anosmia be permanent following a COVID-19 infection?

Loss of sense of smell is a common side effect of COVID-19. However, current research has determined that coronavirus may cause smell dysfunction, but it doesn’t cause permanent anosmia.

Outlook / Prognosis

What can I expect if I have anosmia?

If you’ve been diagnosed with anosmia, your healthcare provider can help manage your symptoms until your sense of smell is restored.

How long can anosmia last?

It depends on the underlying cause of your anosmia. Most of the time, your sense of smell returns once treatment is complete.

How long is anosmia after COVID?

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.

Living With

When should I see my healthcare provider?

Anosmia related to colds, flus and infections usually goes away within a few days. If you have lingering anosmia, schedule a consultation with your healthcare provider.

What questions should I ask my healthcare provider?

If you have anosmia, understanding your condition can put your mind at ease and help you make decisions regarding treatment. Here are a few questions you may want to ask your provider:

• Is my loss of smell due to a cold, flu or infection?
• Do I have an underlying condition that needs to be treated?
• Could any of my medications be causing anosmia?
• Are there other things I can do to restore my sense of smell?

Frequently Asked Questions

Can you taste without smell?

Smell and taste are closely related. Your tongue can detect sweet, sour, salty and bitter tastes. But without your sense of smell, you wouldn’t be able to detect delicate, subtle flavors.

A note from Cleveland Clinic

Most of the time, losing your sense of smell isn’t serious. But there are instances in which anosmia indicates other, more serious health conditions. If you develop sudden or prolonged loss of smell, contact your healthcare provider. They can find the underlying cause of your anosmia and recommend treatments to ease your symptoms.