APPROXIMATELY FIVE PERCENT OF PEOPLE REPORT SMELL and taste dysfunction six months after COVID-19 infection.
Multiply that five percent by 550 million individuals who have reported contracting COVID-19 worldwide, and we get approximately 27 million individuals suffering from smell and taste loss.
Smell is an ancient and essential perception in mammals, with the smell (olfactory) receptor gene family comprising one percent of our genes. With our noses, we can distinguish thousands of airborne chemicals.
Only if you have lost your sense of smell can you fully appreciate the magnitude of the loss. The pandemic is putting smell and taste loss in the spotlight.
COVID and smell loss
You heard the bad news: Upwards of five percent of individuals who suffer from a COVID-19 infection will experience a loff of smell and taste.
Now the good news: Approximately 75 percent of individuals in groups (from several demographics) examined by the researchers, including participants in 18 previous studies worldwide, regained their smell and taste sensations within a month.
Parosmia is a fluctuating distorted smell perception. This altered sensation arises three months (on average) after the initial COVID19 infection. Most individuals experience an unpleasant smell, rendering normally pleasurable activities (such as smelling coffee or enjoying the odor of food).
Tan and colleagues analyzed a series of studies, with the analyzed studies conducted by interviewing patients. However, subjective evaluations such as these tend to underestimate the actual prevalence of smell dysfunction compared with more objective psychophysical tests.
Management of COVID-linked smell loss
The treatment of smell disorders is challenging, with few evidence-based tools available. In terms of COVID-related olfactory dysfunction, most evidence points to the virus targeting supporting cells in the nose lining (nasal neuroepithelium). These cells, rather than the smell-related nerve cells, have the molecular composition allowing for virus entry.
Here is how COVID may create the smell problem: The viral or cell components released by infected supporting cells lead to a widespread reduction in smell receptors and their signaling components in olfactory sensory cells.
After symptom onset, treatment may include smell training, preferably as soon as possible. This approach is the only one that has supportive evidence. Proposed by Thomas Hummel in 2009, olfactory training takes advantage of the unique regenerative capabilities of the nasal lining and nerves.
Patients sniff and try to identify a sequence of four strong scents — typically rose, eucalyptus, lemon, and clove — for 15 seconds twice daily over several months.
The Clinical Olfactory Working Group members overwhelming recommended olfactory training; none recommended antibiotics.
Alternatively, nasal steroids can reduce COVID-related inflammation. Other approaches that show some promise include intranasal vitamin A and supplementation with omega 3 fatty acids and alpha lipoic acid. The target nasal neuroepithelium is at the far back roof of the nasal cavity.
Smell dysfunction is another reason I hope to continue dodging COVID-19 infection. I continue to use appropriate risk-reduction strategies.
The information I provided in this blog is for educational purposes only and does not substitute for professional medical advice. Please consult a medical professional or healthcare provider if you seek medical advice, diagnoses, or treatment. I am not liable for risks or issues associated with using or acting upon the information in this blog.
