THURSDAY, June 4, 2020 (HealthDay News) — Since the start of the COVID-19 pandemic, it’s become clear that many people with the infection lose their sense of smell and taste. And doctors are concerned that some will never get back to normal.
At this point, it’s hard to know how common the symptom is. First, there were anecdotal reports of COVID-19 patients who had lost their ability to smell or taste, said Dr. Nicholas Rowan, an assistant professor of otolaryngology-head and neck surgery at Johns Hopkins University in Baltimore.
And then, he said, studies started to confirm “there’s a lot of truth to it.”
Rowan pointed to one study of patients hospitalized for COVID-19 that used objective tests to detect smell “dysfunction.” Nearly all patients — 98% — showed some loss of smell.
But the problem isn’t limited to severely ill patients. It appears to be common, and even a “cardinal” symptom, among people with milder COVID-19 infections. Cardinal symptoms are the key ones from which a diagnosis is made.
For example, in a study of European patients with mild-to-moderate COVID-19, 86% reported problems with their sense of smell, while a similar percentage had changes in taste perception.
As anyone who’s ever had a cold knows, smell and taste are closely intertwined, Rowan said. So the loss of smell — which doctors call anosmia — may be diminishing people’s perception of flavors.
Respiratory viruses, including cold viruses and the flu, are known to sometimes trigger anosmia.
Fortunately, the issue resolves for most people. “But unfortunately,” Rowan said, “some patients are left with permanent olfactory [smell] dysfunction.”
That’s what has doctors worried — particularly since these sensory problems appear unusually prevalent in people with COVID-19.
“It does happen with other viruses,” said Dr. Daniel Coelho, a professor of otolaryngology-head and neck surgery at Virginia Commonwealth University in Richmond.
“But,” he added, “we’re seeing it a heck of a lot more with this virus.”
It’s not clear why, but Rowan said there’s some evidence that SARS-CoV-2 — the virus that causes COVID-19 — directly infects the area of the olfactory nerve. That might be how the virus gains entry into the body.