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What's the problem with parosmia?

It’s not life threatening, it doesn’t prevent you from getting up in the morning, or going to work. It’s not infectious. So just get over it. This might be the view of some doctors, but not AbScent’s trustee and practising ENT surgeon, Mr Simon Gane.

In our June webinar he talked about the issues that parosmia causes for the patients he sees, and why he’s hopeful that the paper he co-authored with Dr Jane Parker and Chrissi Kelly will be a ‘landmark paper’ in the understanding of this debilitating condition.

There is another kind of smell dysfunction, though, and it is qualitative. It’s a change to the sense of smell where smells seem different. Their quality is changed. You can have parosmia whether you are hyposmic (reduced level of smell) or even a normal sense of smell. 

Types of smell dysfunction

Parosmia - a strong, instinctive disgust response to smells we know should be safe. Triggered by particular odours that vary between patients.
Phantosmia - a background awareness of a chemical or burnt-type smell, not associated with a recognised trigger
Perseveration - a triggered response that then stays in the nose, even though the source is gone.A “smell lock”

Simon explains that the disgust response is a primary response to keep us safe. We instinctively know to avoid things that cause disgust because they will harm us. The smell of rotting meat is universally disgusting to prevent us from eating something that will make us sick. Some smells, like poo, we learn to be unpleasant as we develop our experience of the world.

In parosmia, the disgust response occurs where it wouldn’t normally be. The result is we can’t physically face eating that thing because everything in our primitive security system says no, that’s going to do me harm.

We knew parosmia was a problem before Covid-19 came along. The investigation into a molecular basis for parosmia was started well before the pandemic. But now a lot more people are dealing with these symptoms, so we need to understand why.

Treating parosmia

There are currently no treatments for parosmia, which is why Simon believes understanding the molecules that trigger parosmia is so important. 

Simon explained that parosmia means you have a functional sense of smell. It’s a positive symptom that predicts recovery and if your problem was caused by a virus, you are female and you are young, there is a very good chance of recovering a good and enjoyable sense of smell. “Parosmia is the result of a working system that’s been thrown out of whack, so we need to get it working again” he explains. 

Smell training is the best way to get that system working. And a paper published by Altag Altundag and colleagues demonstrates that it’s effective for people with parosmia. They demonstrated that the more attention you give to smell training, and the more odours you use as you smell train, the better the chance of recovery. 

In addition, we know that the brain is plastic and if we focus more processing power on smell, that in turn is going to build capacity to smell. There is compelling evidence that training changes the structure of the brain (Joe Frasnelli). For example, when they start out, most perfumers have a sense of smell that’s no better than normal, but they spend years training it to be outstanding.

These are natural processes we already use in different aspects of life. The body is already capable of improving, so we just hook into that and use smell training to get back to a good, enjoyable sense of smell.

You can see the full interview with Simon Gane and Dr Jane Parker on AbScent’s YouTube channel

July 12, 2022