Episode 84: Smells in medicine. 

Intro about race in algorithms. Self-reported case of anosmia by Dr. Arreaza. Some common smells in medicine are discussed with Dr Grewal, for example, halitosis, bromhidrosis, and fetor hepaticus. Parosmia is also mentioned as a sequela after COVID-19 infection. 

Intro: Race in clinical algorithms.  
By Brandy Truong, MS4, Ross University School of Medicine.

 

The year 2020 was not only the beginning of the pandemic but also a time when our country finally took the time to learn more about systemic racism. Many members in the medical community have been fighting racism in medicine for years and unfortunately have often gone unheard. However, in the past few years, people decided to start listening. 

The New England Journal of Medicine published an article in 2020 looking at different algorithms that have a race component and how that can be harmful to patients and perpetuates systemic racism. Let’s take a dive into some of those clinical algorithms. 

Something that has gained a large movement, is getting rid of a test that helps determine kidney function based on race. This test is called estimated glomerular filtration rate, or what we call eGFR which considers a person’s age, gender, race, and levels of creatinine. When it comes to the race category, it considers if someone is African American or not. Therefore, there are different normal eGFR values for African American and then all others. 

The test was based on an assumption that Black people have higher muscle mass on average which led to higher kidney function. This becomes problematic because assuming all Black people have higher kidney function can delay a patient’s referral to a specialist or getting a transplant. This leads to higher rates of end-stage kidney disease and death due to kidney failure compared to the overall population. 

Many physicians and medical students at top universities have pushed their administration to get rid of the eGFR values based on race. Some hospitals like Mass General no longer use eGFR based on race. The National Kidney Foundation and American Society of Nephrology are still evaluating if they recommend the current algorithms. 

When it comes to looking at heart failure risk, the American Heart Association recommends a Heart Failure Risk Score that predicts the risk of death in patients admitted to the hospital. When a patient identifies as not Black, their score increases by 3 points which puts Black patients at lower risk due to a lower score. This score helps us decide on referrals to cardiology and general care. This becomes problematic because Black patients may not receive the care they need if assumed they are lower risk. 

This was shown when a study done in 2019 showed that Black and Latinx patients that presented to an emergency department in Boston with heart failure were less likely than White patients to be admitted to the cardiology unit.

Another algorithm that puts Black patients at lower risk is the STONE score which predicts the likelihood of kidney stones in patients who present in the ER with flank pain. The score increases by 3 points for patients who don’t identify as Black, which once again puts Black patients at lower risk due to a lower score. 

Black maternal mortality is drastically much higher compared to White women. Something that can contribute to it is an algorithm called Vaginal Birth after Cesarean which predicts the risk in a trial of labor for someone who had a prior cesarean section. This algorithm predicts a lower level of success for mothers identified as Black or Hispanic. 

It’s also important to note that the study used to create the algorithm found that variables like marital status and insurance type also correlated with the success of vaginal birth after cesarean, but those factors weren’t included in the algorithm. 

The benefits of having a vaginal delivery include lower rates of surgical complications, faster recovery time, and fewer complications in future pregnancies. Nonwhite women have higher rates of c-section than white women which decreases the chances of nonwhite women from having the benefits of vaginal delivery.

We have to ask ourselves, why continue to use algorithms based on race? A lot of these algorithms were based and created on flawed assumptions. And while geneticists want physicians to take race seriously, studies showed there is more variation within the same racial groups than between different ones. And racial differences that are found, it was most likely due to the effects of racism such as the experience of being Black in America. It’s harmful because these algorithms guide clinical decisions which may direct more attention or resources to White patients than patients of color, which is harmful and increases health disparities. 

This segment touches only the surface of algorithms using race to determine clinical outcomes and how that is flawed. There are also many other factors rooted in systemic racism in why these algorithms considered race in the first place, why we continue to use them, and the disparities in healthcare and clinical outcomes. 

As we end this segment, I want to take the time to thank the folks fighting racism in medicine as it’s not an easy task. As people continue to bring awareness, we need to listen, acknowledge, and make changes accordingly so that all patients can have the care they need and deserve.

This is Rio Bravo qWeek, your weekly dose of knowledge brought to you by the Rio Bravo Family Medicine Residency Program from Bakersfield, California. Our program is affiliated with UCLA, and it’s sponsored by Clinica Sierra Vista, Let Us Be Your Healthcare Home.

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Smells in medicine.  
By Hector Arreaza, MD. Discussed with Namdeep Grewal, MD.

Some of my happiest memories are linked to smells, I’m sure specific smells bring back memories to you. In my case, the smell of wet dirt on a rainy day accompanied by the aroma of boiling hot chocolate are some of the smells that remind me of my childhood. From my teen and youth years, I remember some of the trendy colognes among young people: Calvin Klein One, Paco Rabanne, and Hugo Boss are some of those smells that have a little space in my limbic system. 

Olfaction is one of the special senses that we take for granted until we lose it. The term anosmia became more popular after March 2020 because anosmia is one of the symptoms of infection by coronavirus. I got COVID-19 recently and experienced anosmia for the first time in my life. I had a feeling of emptiness in my life. I felt incomplete. I will not deny it was pleasant to drive by a particularly stinky road by my house without gagging or covering my nose, but I was missing the smell of foods and other pleasant smells in my life. 

While I was experiencing anosmia I was not working, but I thought about the effect of my anosmia on my work as a physician. What smells could I miss if I did not recover my olfaction? I also reflected on the smells that I have experienced as a doctor. Some smells have helped me guide a diagnosis or start an investigation. Today, I want to discuss the olfactory system as a diagnostic tool in medicine.

Nowadays, clinicians rely less on their olfactory systems to make a diagnosis, but smells can certainly be helpful in some cases. I was blessed with a very sensitive sense of smell, but honestly, I have a hard time tolerating farts, B.O., bad breath, and other unpleasant smells. 

Halitosis: Also known as “bad breath” can be an indication of poor oral hygiene causing dental decay and gingivitis. Halitosis can be a deal-breaker in a relationship, but it can also be a sign of infections such as tonsillitis, lower respiratory infections (viral or bacterial), Vincent's angina (acute necrotizing ulcerative gingivitis), gastroesophageal reflux, Helicobacter pylori infection, and Zenker's diverticulum (which is a pouch or diverticulum that forms in the upper esophagus causing dysphagia, and food and saliva may get stuck in the pouch and decompose over time, no wonder it may cause a smell, remember the mnemonics for your test “Zenker” = “Stenker”). In patients with foul, feculent breath who are acutely ill you will need to rule out intestinal obstruction or diverticulitis.

An ammonia-like smell can be detected in patients with chronic or acute uremia. If the ammonia is accumulated in the blood to a level that makes it perceptible to your nose, you may be in front of a severe case of renal disease, so refer the patient promptly for 

Bromhidrosis (body odor): Body odor is the perceived unpleasant smell that results from bacteria metabolism of fatty acid by bacteria that normally live on the skin. The apocrine glands are located on the axilla, anogenital area, and breasts. These glands develop around puberty and their function is the secretion of pheromones. Sweat is normally odorless, but the bacteria degrade the sweat, oils, and proteins into substances that produce a strong smell. Body odor is normal. Excessive body odor that interferes with social life and self-esteem is considered bromhidrosis. What is considered “excessive” can vary from one patient to another. The treatment of localized bromhidrosis (mostly axilla) is focused on decreasing the amount of sweat by applying antiperspirants and improving hygiene. Recalcitrant cases of bromhidrosis may be related to infections such as intertrigo and erythrasma and require the use of topical or systemic antibiotics, and severe cases may even require a dermatology evaluation. 

Alcohol breath: I’m very familiar with this smell after many years of encounters with intoxicated people, not only patients but friends, uncles, cousins, etc. The smell of alcohol in exhaled air is used to determine blood alcohol content (BAC) by using a machine called a breathalyzer. All states, including California, consider a BAC above 0.08% as the standard to be legally intoxicated while driving. A caveat about BAC by breathalyzer is that patients following a ketogenic diet may have a falsely elevated BAC. So, make sure to inform the officer about your eating habits to avoid getting an unfair DUI sentence. A BAC level above 0.04% is applied to drivers of commercial vehicles, including moving trucks and rental cars, and a BAC above 0.01% for drivers under the age of 21. Most states have a zero-tolerance for underage drinkers and drivers, and harder penalties for those who have exceptionally high BACs. Alcohol intoxication is more than just a smell, you need to have many other signs and symptoms for diagnosis. If you feel your nose and your judgment are inaccurate, you can confirm by measuring a direct alcohol level in the blood, especially when you are in the hospital and need an exact diagnosis. 

Anaerobic infection smell: Anaerobic bacteria cause wound infections that are characteristically foul-smelling. You can find free gas in tissues, abscesses, and pungent discharge. After smelling infected wounds several times, your nose may be able to recognize the typical foul-smelling odor of anaerobic bacteria. But not all bacteria have an unpleasant smell, according to medical literature, I cannot attest to it, pseudomonas smell like grapes or tortillas, streptococcus smells like butterscotch, and proteus smells like burned chocolate or cocoa.

Diabetic Ketoacidosis (DKA): Patients with DKA may have a fruity smell. Acetone and ethyl acetate are elevated in DKA, and they have a scent similar to nail polish remover. If your patient smells like a beauty salon and is breathing fast and deeply (Kussmaul breathing), there is no time to spare, start immediate treatment of DKA. Remember that DKA can be the initial presentation of diabetes in some patients, particularly young patients, and it is fatal if left untreated.

Fetor hepaticus breath: The description of this smell is somewhat confusing. Some people describe it as a combination of rotten eggs and garlic, others describe it as a smell like clover, or Sulphur with a hint of fecal matter, it is also known as the “breath of death”. The components responsible for this smell are “thiols” that enter the systemic circulation through a portosystemic shunt caused by portal hypertension in liver disease. The thiols reach the lungs and from there they are exhaled giving the chronic liver patient the fetor hepaticus breath. Some people also describe it as a “musty” odor. 

Musty smell: You can think of musty as a synonym of moldy. Musty is likely a variant of the word “moisty,” or “moist.” Musty means having an odor (or flavor) suggestive of mold, such as old buildings or stale food, or like sweaters left in an attic for a long time. Mousy means that it smells like a “mouse”. It can be challenging to know what a mouse smells like. If you want to experience a “mousy” odor, walk into a pet store on a summer day and you may be able to recall the smell when you examine a patient. Why are we talking about musty/mousy odor? Because it can be clinically relevant if you find it in a child’s breath, urine or skin, as this can mean accumulation of phenylalanine in the body, known as phenylketonuria. Detecting a “musty” odor during a physical exam may be less common now because phenylketonuria is included in the newborn screening program in the United States and many other countries. Remember that keyword for your exams, “musty” odor means phenylketonuria.

We have discussed different smells in medicine: halitosis, ammonia, body odor, alcohol breath, anaerobic infection, DKA, fetor hepaticus, and musty smell. We did not cover all smells in medicine, but this is a good starting point for you to keep learning about smells in medicine. 

As for anosmia and COVID-19, let’s remember that most people recover their sense of smell within a few days or weeks, but some patients have reported a long-term abnormal sense of smell, either anosmia or parosmia.

Parosmia is an altered perception of odors that causes normally pleasant smells to be perceived as foul or disgusting. For example, smelling coffee can feel like smelling rotten food. Many patients have reported this symptom after recovery from COVID-19. Parosmia may last 3-6 months, and resolution is normally spontaneous.The cause of parosmia is still uncertain, but it is thought to be a result of direct inflammation of nervous tissue in the olfactory system. As we know, COVID-19 is a multisystemic infection that involves not only the respiratory system but also the nervous system, GI tract, cardiovascular system, and other organs that we are still discovering. There is not a specific treatment for parosmia, but some believe in “smell therapy” which consists of smelling strong scents such as ammonia, eucalyptus, citrus, and perfumes to re-train the brain on the normal process of smelling. 

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Conclusion: Now we conclude our episode number 84 “Smells in medicine.” What is a memorable smell you have? Some smells are characteristic findings of certain diseases. For example, a “musty” odor is a keyword for phenylketonuria. Your nose can point you in the right direction to a diagnosis. If you are among the 1 in 10,000 people with congenital anosmia, don’t worry, there are other ways to sense your surroundings, you can still be an excellent clinician without a sense of smell. Even without trying, every night you go to bed being a little wiser.

Thanks for listening to Rio Bravo qWeek. If you have any feedback about this podcast, contact us by email at RioBravoqWeek@clinicasierravista.org, or visit our website riobravofmrp.org/qweek. This podcast was created for educational purposes only. Visit your primary care physician for additional medical advice. This week we thank Hector Arreaza, Namdeep Grewal, and Brandy Truong. Audio edition: Suraj Amrutia. See you next week! 

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References:

1. Gaffney, Theresa, et al. “A Yearslong Push to Remove Racist Bias from Kidney Testing Gains New Ground.” STAT, 16 July 2020, www.statnews.com/2020/07/17/egfr-race-kidney-test/. 

 

1. Vyas, Darshali A., et al. “Hidden in Plain Sight — Reconsidering the Use of Race Correction in Clinical Algorithms.” New England Journal of Medicine, vol. 383, no. 9, 2020, pp. 874–882., doi:10.1056/nejmms2004740. 

 

1. Miller, Jami L., Bromhidrosis, UpToDate, last updated: Oct 18, 2021, https://www.uptodate.com/contents/bromhidrosis?csi=b679769a-2e96-4c17-bac5-ad299491751d&source=contentShare.

 

1. California Driver Handbook, Alcohol and Drugs, California DMV, English 2020,  https://www.dmv.ca.gov/portal/handbook/california-driver-handbook/alcohol-and-drugs/

 

1. Parosmia After COVID-19: What Is It and How Long Will It Last? Office of Public Affairs, University of Utah Health, September 3, 2021, https://healthcare.utah.edu/healthfeed/postings/2021/09/parosmia.php.

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