Is Parosmia or the Loss of Smell Dangerous?

Interviewer: After getting COVID-19, some people can lose their sense of smell or also suffer a condition called parosmia, which is a distortion of smells that can turn once-pleasant odors into unpleasant ones. Not being able to smell or smell accurately can be an inconvenience and not enjoyable, especially if things like fruit, coffee, chicken, and other foods and things in your environment smell like garbage or chemicals like ammonia. But can it impact a person's physical or emotional health?

Dr. Kristine Smith is a rhinologist, which is a nose and sinus expert, at University of Utah Health. Dr. Smith, is a decrease in the ability to smell or an altered sense of smell dangerous?

Dr. Smith: You know, kind of shortest, simple answer is that losing your sense of smell or having a change in your sense of smell is not going to directly cause you harm by not having it, but it does increase your risk of some other potential harmful things. The ones that I try to really emphasize for patients is when your sense of smell comes back wrong, or when it's decreased long term, this does actually put you at an increased risk for experiencing food poisoning over time because you might not be able to tell when something has gone bad in your fridge. And so a really careful attention to the expiry dates on food in your fridge and labeling your leftovers so you know how long they've been there for, or having someone in your home who has a normal sense of smell check them before you eat them is actually really important.

And then similarly, you might not be able to detect smoke or natural gas in your home with your altered sense of smell, and so ensuring that you have up-to-date smoke detectors and natural gas detectors is really important. Even if you have a natural gas stove, potentially getting a handheld natural gas detector can be really important because it might be that you went to light your stove, the lighter didn't work, and then the gas is kind of spewing out of the stove, and you try to relight it, and there's been an accumulation of that gas in your home, which can potentially cause a small explosion. And so it's something I'm very careful to talk to patients about so that they're aware of that potential risk. Barbecues are another area where that can be really problematic.

Similarly, we can see occupational disruptions in our patients that are experiencing parosmia, particularly people that work in the food industry, like chefs, or potentially in other areas like florists or firefighters, who are dependent on their sense of smell to do their job well, and so this can be very impactful for patients.

Outside of those kind of like lifestyle risks that we talked about, changes in your sense of smell actually has the potential to significantly impact your mental health. So your ability to smell, your ability to enjoy food from the flavor that comes from your sense of smell is really important for our well-being long term, and these types of alterations have a really significant impact in the quality of life of our patients.

They do feel very bothered by these symptoms, and they do affect their enjoyment of life on a day-to-day basis. And so having persistent parosmia, having persistent hyposmia can increase your risk potentially for things like anxiety or depression. And I think making sure that our patients are aware of this is really important so that if they start to experience those symptoms, if they start to think that maybe they're being affected by this, we can help to treat those associated issues, those associated anxiety and depression, so that we can mitigate the impact that this is having as much as we can.

Interviewer: I can see how the mental impacts could be very real, especially with I've heard patients reporting that other people in their lives have a hard time understanding what they're going through. Have you experienced that with your patients?

Dr. Smith: Yeah. I would say that's absolutely true. Parosmia, phantosmia, hyposmia are extremely difficult to understand unless you've lived them. And I think most people have had a cold or an upper respiratory tract infection where they've had a weird sense of smell or taste for a short period of time, and they're like, you know, "Nothing tastes good. I don't want to eat while I'm feeling sick." And now imagine if that's what your life is like every day forever. And it can potentially cause real distress when patients can't enjoy things that they normally would enjoy.

So, you know, I personally had COVID-19 in April, and when I was recovering, I actually did have some parosmia phantosmia as I was recovering, and one of the things that I no longer enjoyed was coffee. And I'm a big coffee drinker. I love my morning cup of coffee. And it got to the point where I could not drink my coffee and keep it down because the smell that was associated with it was so terrible. It was making me so nauseated, I couldn't drink it anymore. We had to take all the coffee beans out of our espresso machine and put them away for a while because I just couldn't tolerate them being in the home, and I was really upset about that. I was really bothered about that, and I thought, you know, "This is going to last forever. I'm never going to be able to have a good cup of coffee again." And, you know, fortunately for me, slowly over time that improved, and now I can have my morning cup of coffee again.

But for some patients it's not restricted to one food or to one drink. And it's very bothersome for them. I think it's important that we acknowledge how severely this can impact their life and their day-to-day living because it is a real problem.

Interviewer: And as far as not getting the nutrients that somebody needs because of parosmia, is that a threat? Is that something that maybe somebody should see a dietician about?

Dr. Smith: I think that's a great idea. So if you find that your trigger foods are leading you to eliminate an entire food group from your diet, like meat, this is really going to significantly impact your intake of proteins, of vitamins and minerals, and as you start to restrict your diet using those avoidance measures, you want to make sure that you're still getting a well-rounded diet.

This can be particularly disruptive in an older generation of patients. As you get a little bit older or wiser, one of the things that happens is that your sense of smell starts to diminish naturally over time, and this can be particularly bothersome to patients when it comes to their enjoyment of food. And so if you get an additional disruption to that with COVID-19, it kind of adds a stepwise worsening to that process.

And so one of the reasons that we see folks eating less as they get older and wiser is because their enjoyment of food has decreased in addition to their appetite, and it can be really hard to motivate someone to eat when everything tastes really bland or when it tastes bad. And subsequently, you can have potentially an increased risk of anxiety and depression associated with those things. And so this is something that I think it's important to be mindful of in our older generation so that we can keep an eye out for it and help to manage it as it's becoming a problem.

Interviewer: What would you say to somebody who has parosmia and they're listening to this? What would be the most important message you could give them?

Dr. Smith: Honestly, I think there are two things. The first and most important is that you are definitely not alone. There are so many other patients who are experiencing this. There is a whole growing community of people like you that can help you to kind of get through this stage of your life. It's unfortunately common. We are seeing a lot of it. You are not alone.

The second thing is that it seems to get better. The vast majority of people, you know, 90% plus, within two years of having their COVID-19 infection report that these alterations in their sense of smell go away despite doing nothing about it. And so, for the vast majority of people, it is going to get better with time. It is very slow. We used to think that nerve healing kind of whatever you had one year after the injury, or one year after your episode of COVID-19, was what you were going to be stuck with long term, and we know now that that's not true. It keeps improving two years, three years after you've had the infection, and things seem to slowly get better over time. So don't lose hope. It is very slow. I know that it's hard and it's disruptive, but it does seem to get better for the vast majority of people slowly over time.