Parosmia (Distorted Smell) After COVID: What You Should Know

A loss of your sense of smell, known as anosmia, is one of the most common symptoms of COVID. However, COVID can impact your sense of smell in another way through parosmia—which is smell distortion.

Parosmia, also called "COVID smell," typically occurs months after you have COVID. This could happen even if you didn't lose the sense of smell when you had COVID. Here's what else you need to know.

What Is Parosmia?

Parosmia happens when a person has smell distortion. Symptoms that indicate a person may have parosmia include:

• Experiencing a familiar odor that doesn't smell the way it's expected to smell
• Having an inability to tolerate the smells, which can result in gagging or vomiting
• Smelling pleasant odors as unpleasant smells like rotting, burning, or sewage odors

Its causes include upper respiratory tract infections, head trauma, and neurodegenerative diseases such as Alzheimer's disease. Foods like coffee, onion, meat, citrus, or garlic can trigger parosmia attacks.

Can You Get Parosmia After COVID?

Parosmia has been shown to develop after COVID, often due to anosmia. However, though anosmia and parosmia are connected, you may not experience parosmia as a telltale symptom of COVID. Unlike anosmia, it's not an early-stage symptom of the illness. Additionally, parosmia may be a sign that you've recovered from COVID completely, but it can affect your quality of life.

How Common Is It?

Parosmia is common in people with smell issues during a COVID infection. One study found that 75% of individuals with COVID have smell disorders, with 45% experiencing parosmia.

Also, about 10% of people who experienced smell-related problems during COVID may develop parosmia as they begin to recover. One study found that about 64% of participants with post-COVID smell dysfunction had parosmia.

How Long Does It Last?

Parosmia due to COVID might last for a long time. Some researchers indicated that, according to some patient reports, cases of parosmia have lasted up to 16 months. However, they also stated uncertainty about whether it is permanent as a result of COVID.

When a person has parosmia, it can affect their experiences with food and other smells. Also, parosmia severity can fluctuate and make you feel worse on some days compared to others. However, the fluctuations will progressively even out.

What Are the Risk Factors?

Suggested risk factors for developing parosmia associated with COVID include:

• Assignment of female sex at birth
• Development of early smell dysfunction during COVID infection
• Limited history of chronic sinusitis or growths within the nasal cavity or sinuses
  
• Younger age

How Is It Treated?

Researchers explained that treatments backed by evidence for individuals with parosmia are unavailable. Some medications—like antipsychotics, antiseizure medications, and gabapentin—have been used as treatment options. However, their effectiveness has varied.

Additionally, one study showed that Modified Olfactory Training (MOT) for 36 weeks effectively treated post-COVID parosmia. This training involved smelling certain scents—such as those of eucalyptus, lemon, clove, and rose—multiple times.

Each smelling session lasted for 10 seconds with 10-second breaks in between. The training took five minutes and was meant to be performed twice daily. The selected scents changed every 12 weeks. Ultimately, the training group saw more improvement with parosmia compared to the control group.

How to Manage Parosmia

Though researchers are still studying parosmia treatments, there are some practical management tips for those with smell distortion:

• Keep track of foods that trigger your parosmia and let the people around you know what they are.
• Because parosmia triggers can change, keep trying new things to find your "safe" foods.
• Consider eating foods that are cold or at room temperature—they give off less odor.
  

A Quick Review

You may be more likely to develop parosmia, or smell distortion, if you have certain risk factors—like having smell problems in general during a COVID infection. Parosmia due to COVID can occur long-term; however, there's not enough research to determine if it is permanent.

Research is also ongoing for evidence-based parosmia treatments, though it may be possible to manage the symptoms. Talk to a healthcare provider or dietitian if you have severe parosmia affecting your ability to eat and your quality of life.