Philly society photographer HughE Dillon was diagnosed with COVID-19 after he started having symptoms of the infection last Monday. About a week later, he couldn’t stomach the taste of his favorite tea.

“Everyday I get the same iced tea,” Dillon said about the drink delivered and left on his doorstep by Fairmount restaurant Little Pete’s. “It’s my favorite and I was like, ‘Ugh, it tastes like sewer water. What happened?’”

It’s been that way for days, he said. “Hot tea, water, ice tea…they all taste the same.” Then he saw a New York Times report linking taste and smell loss to COVID-19, and the blah flavors suddenly made sense.

Earlier this year, Dillon came down with a case of the flu that left him bedridden. So far, his seemingly mild case of COVID-19 feels different. “You can get up,” he said, “but sometimes you’re nauseous, sometimes your body aches.

“I want hope,” Dillon said. “I mean, I’m sure I’m going to be fine.”

Loss of the sense of smell, called anosmia, is a known symptom of many viral infections.

Also referred to as “smell blindness,” it happens to many people when they catch the common cold — which itself is caused by a strain of coronavirus. However, the condition’s relationship to the global pandemic that’s infected nearly 400,000 people and killed more than 16,000 worldwide remains unclear.

It does sound like Dillon is experiencing anosmia, or dysgeusia, a distorted sense of taste, said Dr. Pei-Hua Jiang, a faculty member at Monell Chemical Senses Center. The University City institution is the world’s only nonprofit research institute devoted to the study of taste and smell. Monell VP and associate director Dr. Nancy Rawson agreed with the assessment.

But both scientists said that with a condition this new, anecdotal evidence may not be enough to draw a direct connection. “You have to do this scientifically,” said Jiang.

Causing concern in Britain, Korea and Germany

In one study of 2,000 COVID-19 patients in South Korea, about 30% of patients reported a loss of smell and taste.

A smaller German study of just under 100 patients found that two-thirds experienced it. And in Italy, one of the nations hardest hit by the coronavirus pandemic, doctors are sharing information that anosmia could be an indication of COVID-19 in patients showing no other symptoms.

Ear, nose and throat specialists in Britain have begun to advise anyone experiencing loss of smell and taste, even as a lone symptom, to self-isolate. They’ve also advised doctors to use personal protective equipment (PPE) while treating patients experiencing new anosmia symptoms.

“If anosmia was added to the current symptom criteria used to trigger quarantine…we might potentially be able to reduce the number of otherwise asymptomatic individuals who continue to act as” COVID-19 carriers, the British ENT doctors wrote in an advisory on Mar. 20.

In general, experts theorize viruses cause anosmia by interfering with the function of olfactory neurons, needed to transmit scents to the brain. This interference translates as a lack of taste, because the brain’s perception of flavor is caused by a mix of taste and smell.

It’s typical for the condition to show up days after initial viral symptoms like fever and cough occur, according to the Monell scientists, as it did in the case of Dillon, the Philly photographer.

But even though Dillon tested positive for the coronavirus causing COVID-19, it’s not clear that his anosmia is directly related.

After a virus of this type infects someone, it can hijack or weaken the body’s immune system and leave the person susceptible to additional infections. This has been documented in many COVID-19 cases.

“It could be not the virus itself, it could be related to these secondary infections,” Dr. Rawson told Billy Penn about the loss of smell. “I don’t think we really understand why many of the patients with COVID also have these secondary infections.”

Philly not using anosmia as a trigger symptom, yet

By Monday, Philadelphia had recorded 175 cases of the novel coronavirus, contributing to the nearly 700 positives across Pennsylvania, out of about 7,000 people tested.

Philly’s not ready to officially name anosmia as a COVID-19 symptom yet, according to Health Commissioner Tom Farley said.

“I think that’s very non-specific and can happen with other illnesses,” Farley said during the city’s daily briefing on its coronavirus response. “We’re really looking at fever and dry cough.”

The city isn’t collecting information on whether or not COVID-19 patients report anosmia, Farley added.

It’s not unusual for these sensory symptoms to be overlooked when dealing with viral diseases, according to the Monell scientists. “I think they’re so focused on respiratory,” Rawson said, “doctors tend to kind of overlook taste and smell.”

Rawson said researchers around the world have organized to create the Global Consortium for Chemosensory Research to “collect scientifically reliable data regarding taste and smell function in patients with or recovering from COVID-19.”

Scientists at Monell will be involved in the effort.