A Change in Smell After COVID

Being able to taste and smell are essential parts of enjoying everyday life. But for some COVID-19 long haulers, these senses can become extremely unpleasant. Some people experience a change to their taste and smell following COVID-19 infection, also known as parosmia (abnormal sense of smell), hyposmia (decreased sense of smell), and anosmia (loss of sense of smell). The good news is it's usually only temporary—in most cases. However, no matter how long these conditions last, it can be very disruptive.

Kristine Smith, MD, a rhinologist and assistant professor in the Division of Otolaryngology (Head and Neck Surgery) at University of Utah Health, answers eight questions about parosmia.

While it's not known exactly what triggers parosmia, smell disruption can be caused by viral illnesses such as the common cold or influenza. Head trauma, medications, and neurologic diseases such as Parkinson's and other neurodegenerative diseases can also cause parosmia. During a viral illness, the nerve receptors in your nose can be damaged and change your perception of smell. It's believed this same phenomenon occurs during COVID-19 infection.

A loss of taste and smell is a common symptom of COVID-19 infection. In the recovery phase of COVID-19, a patient normally regains their senses back. However, some people experience a change to their sense of smell about three to four months following infection. People report certain things—like food or body odor—smelling like garbage, rotten eggs, or chemicals. This altered sense of smell is called parosmia.

The number of patients who experience a loss of smell and taste during or after COVID-19 infection ranged widely. The loss or change of taste and smell during COVID-19 infection impacts about 50-75 percent of people. About 25-75 percent go on to develop parosmia in the recovery phase of COVID-19.

Patients usually improve slowly with time. About 65 percent of people with COVID-19-induced parosmia or hyposmia regain these senses by about 18 months, while 80-90 percent regain these senses by two years.

If you lose your sense of smell or have a reduction in your sense of smell while you have COVID-19, you are more likely to develop a disturbance in your sense of smell later. But you can still experience parosmia even if you didn't originally have smell loss. Patients who are younger and female also seem to have a higher incidence of experiencing post-COVID-19 smell disruption. It's unclear why these groups are more impacted.

The number of people reporting parosmia seems to be changing with COVID-19 variants over time. More cases of parosmia were reported at the beginning of the pandemic with the original SARS-CoV-2 virus. While patients are still experiencing parosmia, the number of patients seeking help with their symptoms is less with the newer variants.

There are no guaranteed treatments for post-COVID-19 parosmia. However, some therapies may help some patients. These include:

Other therapies like stellate ganglion blocks, alpha-lipoic acid, and plasma-rich plasma (PRP) injection are being investigated as potential treatments for COVID-induced parosmia. The risks or potential benefits are not yet known.

Home or natural therapies are becoming increasingly common, but DO NOT try these without talking to your doctor first. What you put in your nose could be absorbed in your bloodstream, which could potentially be dangerous to your health.

Losing your sense of smell or having a change in your sense of smell is not going to directly cause you harm, but it can increase your risk of some potentially harmful things, such as: