Dr. Hao “Mimi” Tran recently received a call from one of her dear friends who asked, “Is loss of smell or taste a symptom of coronavirus? Will I get my sense of smell and taste back?” Her friend had recently contracted coronavirus, COVID-19, and was still in quarantine.

She found out she had the virus 8 days after testing.

Interestingly, in some cases, sudden loss of smell or taste may be the only symptom of COVID-19. This has been seen worldwide according to doctors in France, Northern Italy, the UK, Germany and South Korea.

It seems to occur in younger patients under 40 without the other hallmark symptoms of COVID-19.

It seems to occur in younger patients under 40 without the other hallmark symptoms of COVID-19, including fever, cough and shortness of breath. In Germany, it is reported that more than 2 in 3 confirmed cases have anosmia, or loss of smell. In South Korea, where testing has been more widespread, 30% of patients testing positive have had anosmia as their main symptom.

Based upon this clinical observation, it has been recommended by ENTUK and the American Academy of Otolaryngology to add acute loss of smell or taste as a screening question for patients who may have COVID-19. If they answer “yes” and testing is not available, then they should self-quarantine for 14 days.

Why Would You Lose Your Sense of Smell with Coronavirus?

In most other viral infections that affect the upper respiratory mucosa, such as the common cold or flu, most patients will regain their sense of smell and taste. One of the reasons for loss of smell and taste during a viral illness is due to swelling of the nasal lining. This causes obstruction of airflow and decreased ability for odor molecules to reach the smell nerve receptors located high up in the nose under the frontal lobe of the brain. Once the infection improves and swelling goes down, smell function returns to normal. However, in more prolonged cases of postviral anosmia, there may be damage to the smell nerve receptors and recovery may be gradual and take up to 2 years to improve, although in some cases there is no improvement.

If COVID-19 behaves like other strains of coronavirus that cause upper respiratory infections, then most patients will improve but it is difficult to determine at this time since it is so new.

What Should You Do if You Lose Your Sense of Smell or Taste?

If loss of smell persists after several weeks, it is recommended to see an ENT physician and undergo a smell test and a more detailed exam to see if there is a bacterial sinus infection, nasal polyps or other reasons for acute sudden loss of smell. For viral related anosmia, it has been shown in some studies that medications such as nasal steroid sprays and oral steroids may hasten recovery. However, oral steroids should be used cautiously as systemic steroids can temporarily decrease function of the immune system. Several studies have shown positive results using smell exercises for prolonged cases of smell dysfunction. This involves using essential oils and sniffing the odor 2 times per day for several months. It is thought that these smell exercises can lead to regeneration of smell nerve tissue.

Dr. Tran says her friend still has not recovered her sense of smell, but her sense of taste has partially improved. “Her departing words on our last call were, ‘at least I am alive, breathing and able to enjoy cheap wine,’” jokes Dr. Tran.