A physician infected by the novel coronavirus is starting to get his sense of smell back — but can only smell foul odors.

Dr. Douglas Dieterich, a hepatologist at Mount Sinai Hospital in New York City, completely lost his sense of smell when he was infected with COVID-19 in March. After weeks in the ICU unit and months of physical therapy, the doctor told Fox News he is starting to recover and so is his sense of smell —  but only for unsavory aromas.

“I took off my shoes and my socks and got a real whiff of my stinky socks,” Dieterich said. "I rejoiced that I could smell again."

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But when the physician’s friend who was visiting him commented on how good Dieterich’s orange smelled, the doctor realized he could not smell the fragrant fruit. Dieterich tested his smell further.

“I tested my sense of smell by putting my face into a can of coffee. Nothing. I couldn’t smell a thing," he said.

Dr. Douglas Dieterich told Fox News he only can smell foul odors following his battle with the novel coronavirus. Losing one's ability to smell is a symptom of of COVID-19.

Dr. Douglas Dieterich told Fox News he only can smell foul odors following his battle with the novel coronavirus. Losing one's ability to smell is a symptom of of COVID-19. (Dr. Douglas Dieterich)

“I had anosmia which is the loss of sense of smell which is typical with COVID-19," the physician explained, adding that he discussed this specific return of only unpleasant-smelling odors with his neurologist.

“Unfortunately, I learned from the neurologist that there are two pathways of smell and one is for foul odors and one is for nice stuff. So far only the stinky pathway has returned," he said.

“There are two sensory systems in our nose. We are able to detect pleasant fragrances by way of the olfactory nerve. Whereas dangerous, toxic smells are detected by the trigeminal nerve.” Dr. Susan Shin, and assistant professor of neurology at Mount Sinai Hospital, told Fox News. “The trigeminal nerve is likely more resilient to effects of a viral pathogen compared to the olfactory nerve because we need it to detect dangers in our environment such as smelling smoke from a fire.”

Dr. Alfred-Marc Iloreta, Jr., an ear nose throat specialist in Mount Sinai Hospital’s Otolaryngology Department, told Fox News that the novel coronavirus typically affects an infected patient's sense of smell.

“We think that the COVID-19 virus is attacking either the sensory organ for smell called the olfactory nerve directly or the supporting cells around the nerve," he said.

This causes inflammation or direct damage to the nerve that inhibits or limits the perception of smell," Iloreta, who is also an assistant professor of otolaryngology, added.

Iloreta further explained this inflammation can in some cases alter the COVID-19 patient’s ability to identify a smell, noting that some "perceive different smells than before or even phantom smells."

There are many studies being done about coronavirus and its link to smell, including a recent one from Harvard University.

Iloreta’s group at Mt. Sinai Hospital is conducting its own research using scratch and sniff scorecards that patients with COVID-19 use to rate how keen their sense of smell is as it returns. Iloreta said his group is currently studying the effects fish oil supplementation has on patients who lost their sense of smell due to the virus. The randomized controlled trial builds on a study out of Stanford that used fish oil to help post-surgical patients recover smell after certain surgeries.

“We are trying to expand on her research and using it in the large COVID population in NYC," he said.

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Iloreta said the study may help a person’s quality of life.

“Smell and taste are intimately connected and slight alteration in smell can drastically affect the taste," the physician said. "Research has shown that loss of smell in the long term can affect mood."

As for Dr. Dieterich, he looks forward to one day smelling his morning cup of coffee instead of his sweaty socks, he said.