Parosmia: What it is, Symptoms, Causes, and Treatment

Published January 6th, 2022 by Corey Riley
Fact Checked by
Jacqueline Hensler
Medically Reviewed:
Chris Riley

Parosmia 101 | Causes | COVID-19 Link | Diagnosis | Treatment

Parosmia is an olfactory disorder where you have a distorted perception of smell and you may smell odors differently than you should. It can be caused by head trauma, viral infections, or even COVID-19.

If you suffer from parosmia, you usually experience difficulty in odor perception such as distinguishing between foul and fragrant odors.

Though parosmia typically does not have any long-term effects, it can be frustrating if you experience these symptoms and can lead to an aversion to eating and lower your quality of life.

We'll go into detail about what parosmia is, symptoms of parosmia, how parosmia is diagnosed and treated, as well as how it links to COVID-19.

What is parosmia?

Parosmia is a rare condition that affects your sense of smell or olfactory function. It can cause you to distort your sense of smell and perceive smells differently than other people.

You may also experience smells with less intensity as you did before having parosmia.

This condition can also distort the scent of smells, such as an odor that is pleasant may now smell foul and unpleasant.

Parosmia is not the same as phantosmia, which is a condition where you smell different fragrances that are not present at all.

What are the symptoms of parosmia?

The symptoms of parosmia cause olfactory dysfunction and can vary from one person to another.

You may experience a distorted sense of smell that is different from what it was before parosmia set in and the condition might also cause you to lose your appetite because food doesn't taste as good as it used to.

You might also start to avoid certain smells because they are too overpowering or unpleasant for you.

This may mean that certain foods you liked before maybe become inedible due to overpowering foul odors which can lead to nausea.

Parosmia is not the same as anosmia, which is the complete loss of smell.

What causes parosmia?

Parosmia can be caused by many different things.

It could be a result of a head injury, brain tumor, or stroke, among other factors.

parsomia treatment image

In some cases, it is unknown what specifically triggers parosmia. Below are some of the leading causes.

Head injury and brain trauma

If you have a head injury or a traumatic brain injury, it could lead to parosmia.

This is because when your head is injured, the part of the brain relating to smell can be damaged, which in turn might affect your sense of smell.

Brain tumor

A brain tumor can also cause parosmia as tumors can put pressure on certain areas of the brain that are responsible for controlling different senses.

Stroke

Parosmia can be a complication of having a stroke that affects the parietal region which is the part of your brain responsible for controlling smell signals.

In this case, parosmia may occur on only one side and not both sides as with other types of strokes.

This is because it can affect either the right or left side of the brain.

Sinus problems

Sinus problems such as chronic sinusitis can also lead to parosmia.

This is because the paranasal sinuses are located near your nose and send nerve impulses to your brain, specifically the olfactory bulb, which then sends signals back to tell you what smells there are in a certain area around you.

If this mechanism malfunctions, it could be because there is a blockage or nasal obstruction in your nasal cavity which may lead to parosmia.

Bacterial/Viral infection

Parosmia can also be caused by a bacterial or viral infection. A simple cold, flu, or virus can cause parosmia and it often coincides if you are suffering from an upper respiratory tract infection.

Radiation and chemotherapy

Radiation therapy and chemotherapy can also be a cause of parosmia. It usually only lasts for the duration of your treatments.

Chemical exposure

If you are exposed to certain chemicals, it could also trigger parosmia.

This might be from working in a hazardous environment or even using certain personal care products that have strong fragrances. Smoking can also cause parosmia.

Neurological conditions

Alzheimer's disease and Parkinson's disease are two neurological disorders that can cause parosmia along with several others.

Not being able to smell things properly is one of the first symptoms of both diseases, as well as a loss of sense of smell.

How is parosmia linked with COVID-19?

One of the most common symptoms of a COVID-19 infection is anosmia, or the inability to smell anything which is usually coupled with a loss of a sense of taste.

When recovering from COVID-19 and anosmia, some patients have experienced parosmia where things smell foul or differently.

This is very rare and it is uncertain why it happens although some doctors believe it means your olfactory system is beginning to recover from anosmia and the loss of taste.

How do doctors diagnose parosmia?

There is not a specific test to diagnose parosmia. Your doctor will usually ask you about your symptoms and do some tests to rule out other causes of smell dysfunction such as anosmia or hyposmia, which is where your ability to smell things is lessened or reduced.

You may also have to go see an otolaryngologist, which is an ear, nose, and throat doctor.

MRIs, or magnetic resonance imaging, CT scans, or computerized tomography, and biopsies may be used if the doctor suspects a tumor.

How do you treat parosmia?

There is no one-size-fits-all treatment for parosmia and the duration of parosmia is also varied as it can become permanent and the smell function in patients never returns.

Some patients with parosmia recover from it on their own and others need to seek medical attention in order to get help with it.

If parosmia is caused by a certain condition such as brain injury or sinus problem, treating that particular cause may be enough to alleviate parosmia symptoms.

If parosmia is a side effect of radiation or chemotherapy, it will usually go away once the treatments have stopped. If smoking or chemicals are the cause, your symptoms should alleviate once you remove those triggers.

When parosmia is caused by a tumor, surgery to remove the tumor should help with parosmia.

Your doctor may also prescribe antibiotics, especially if it is caused by an infection.

You may want to look into olfactory training therapy, also known as smell training, which is used to retrain your sense of smell.

From around the web: parosmia treatment, how to get rid of parosmia:

Reddit - How to get rid of parosmia
Reddit - parosmia treatment

Are there any long-term effects of parosmia?

There is not much research on parosmia. Parosmia is not usually permanent, although it can be in some cases.

Some people with parosmia may find that their normal sense of smell may never return.

There is also a risk of weight loss and malnutrition due to not being able to eat foods without an unpleasant stench. If you experience any symptoms of parosmia, please see your doctor.

Summary

Parosmia is a condition where your olfactory perception is distorted and your perception of odors will be different than it was before as normally pleasant odors will now smell foul or rotten.

Parosmia can be caused by a number of different factors, such as an infection, radiation therapy or chemotherapy, chemical exposure, neurological conditions, or by recovering from COVID-19.

There is no one-size-fits-all treatment for parosmia and it often goes away once the cause is treated.

There may be some long-term effects of parosmia, such as a changed sense of smell or weight loss and malnutrition.

If you are experiencing any symptoms of parosmia, please see your doctor or medical professional for help.

References and Sources:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7998087/

https://pmj.bmj.com/content/early/2021/03/31/postgradmedj-2021-139855

https://jamanetwork.com/journals/jamaotolaryngology/fullarticle/648666

Published January 6th, 2022 by Corey Riley
Fact Checked by
Jacqueline Hensler
Medically Reviewed:
Chris Riley

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