Moderate Covid-19 cases are more likely to lose their sense of smell, study finds

For people with mild covid-19, the nose can know more than any other part of the body. New research released on Wednesday suggests that almost 90 percent of people with mild illness experience of losing smell, a greater proportion than those with more serious illnesses. Although usually temporary, this loss of smell can last six months and even meOnger.

The search, Published in the Journal of Internal Medicine, he analyzed the medical records of more than 2,500 covid-19 patients who sought care at one of 18 hospitals across Europe. Most were outpatients diagnosed with mild to moderate symptoms, while others were hospitalized with severe or critical covid-19.

In all, about three quarters of patients reported a loss of smell, clinically known as anosmia. But there was a big gap in the presentation of this symptom at different levels of severity. Among patients with mild illnesses, 86% reported loss of smell, compared to only 4.5% of moderate patients and 6.9% of critically ill patients. When looking only at patients who had their smell loss confirmed through objective tests, this gap narrowed, but remained: 54.7% of these milder cases had loss of smell confirmed, compared with 36.6% of moderate to critical cases.

“Olfactory dysfunction is a prevalent disorder in covid-19 patients, with a higher prevalence in patients with mild forms of the disease,” wrote the authors.

The results are in agreement with previous studies, showing that anosmia is a very common symptom of covid-19 – although one that was underreported in the early days of the pandemic. Another research suggested that milder cases tend to have anosmia more frequently. But the new study is one of the largest of its kind to examine its prevalence and have data from patients who had their anosmia confirmed with tests.

Although this study cannot tell us why the milder cases are more prone to lose sense of smell, the authors have theories. The main explanation is that anosmia it is ironically a sign that the body is doing a decent job of defending itself from the coronavirus. In these patients, the infection never spreads far beyond the upper respiratory tract, thanks to a robust and localized immune response. But this answer it can lead to inflammation that damages or interferes with nearby cells that help us process the smell, at least for a short time.

There may also be some misunderstanding going on for more serious cases. Patients in the hospital often deal with many varied symptoms, while the most critical patients may need intensive interventions, such as a feeding tube or ventilation. Ppatients with more severe covid-19 may simply not notice its anosmia while it is happening. This could explain the higher rates of anosmia in the study between moderatesfor-serious cases that have actually been examined.

Fortunately, for most people who has anosmia related to greed, seems to be self-limiting. The median duration in patients was about three weeks, with about a third reporting that it only lasted two weeks. But 15% of the patients examined objectively lost their sense of smell for at least two months, while just under 5% have not yet recovered by age six.brand of the month. Those with more severe anosmia at first they were more likely to continue experimenting months later.

The authors theorize that cases of short-term anosmia they often represent nothing more than nasal congestion and swelling commonly seen in colds of the day and can momentarily block our ability to smell. But those with persistent anosmia they probably have a more complicated problem on their hands, which means major damage olfactory cells, either by infection or inflammation. While most people who contract covid-19 will be able to smell as much as they want afterwards, the size of the pandemic – with 86 million confirmed cases worldwide in early January – means that many people can lose their sense of smell permanently.

The authors hope that their research will lead to future studies that keep an eye on these long-term cases to better understand the phenomenon, as well as discover how improve a person’s chance of recovery.