Why does the new coronavirus cause a loss of smell in patients?

According tomedia BGR, one of the strangest symptoms associated with the new coronavirus involves smell. Doctors noticed in the first months of the pandemic that some PATIENTs with COVID-19 complained of sudden loss of smell and taste, apparently caused by the virus. Studies have shown a correlation between this symptom and COVID-19, and loss of sense of smell is now a symptom of doctor screening. This was also mentioned on the CDC’s COVID-19 page.

However, not all people experience the symptoms of loss of smell, so symptoms alone are not sufficient to diagnose. Moreover, not all people can regain their sense of smell at the same rate. And a new report explains what happens inside the nose once the virus invades.

Researchers from Harvard University published a study in March that explained how the virus infects olfactory epithelial cells inside the nose. They looked at the genes of these cells and found that the virus did not actually bind to neurons that sensed odors. Instead, the virus infects support ingons in the olfactory region. More than a month later, a different study showed that early COVID-19 screening tests should cover the olfactory epithelial. This can speed up the detection of cases, especially in asymptomatic populations that may not exhibit loss of smell.

Why does the new coronavirus cause a loss of smell in patients?

Citing a study in March, the two doctors co-wrote an article in The Conversation explaining the loss of sense of smell. The report explains not only the sudden loss of smell, but also why some people may take longer than others to regain their sense of smell. Simon Gane and Jane Parker say loss of smell may be common in colds caused by other coronaviruses. But it only happens because of congestion. A blocked nose can prevent odors from reaching the olfactory epithelial skin. As soon as the symptoms are removed, the odor recovers immediately. The new crown virus has a different pattern, because the nose is not blocked.

“Now that we’ve had a CT scan of the nose and sinuses of patients with COVID-19 olfactory loss, we can see that the part of the nose responsible for the olfactory – the olfactory fissure, blocked by swollen soft tissue and mucus – is called olfactory-cracksyndrome. “The rest of the nose and sinuses looked normal, and there was no problem breathing through the nose, ” the two scientists wrote. “

Gane is a consultant to the University of London’s nasal and otolaryngologists, while Parke is an associate professor of chemistry at the University of Reading. Gane and Parker explain that it is clear that the new coronavirus infects olfactory-supported cells through the same ACE2 receptor. These proteins are available in these olfactory cells, lungs and other organs.

“We expect these supporting cells to be most likely virus-damaged cells, and the immune response will cause swelling in the region, but will keep olfactory neurons intact,” they said. “When the immune system deals with the virus, the swelling subsides and the aroma molecule has a clear route to its undamaged receptor, and the sense of smell returns to normal. “

However, for some PATIENTs with COVID-19, it is unusual that they have to wait weeks after the symptoms have disappeared before they can start to start starting to smell again. The explanation may be related to how inflammation progresses. Neurons may not be directly damaged by the virus, but they are affected by inflammation in the region.

“Inflammation is the body’s response to damage and causes the release of chemicals that destroy the tissue involved,” the researchers explained. “When this inflammation is severe, other nearby cells begin to be destroyed or destroyed by this ‘splash damage’. We believe this is the second stage, where olfactory neurons are damaged. “