London researchers studying smell loss in COVID-19 patients

A woman smells an apple. File photo courtesy of © Can Stock Photo / pressmaster

Researchers in London are joining others around the world in a joint study into the loss of smell among COVID-19 patients.

Lawson Health Research Institute and Western University scientists, as well as others in the Global Consortium for Chemosensory Research (GCCR), are asking people with confirmed or presumptive cases of COVID-19 to take a survey regarding the possible symptom.

Currently, there is evidence to suggest more than 60 per cent of COVID-19 patients experienced a sudden loss of smell, known as anosmia, as their first symptom of the illness. However, more research is required.

“While a sudden loss of smell is relatively rare, it is most commonly caused by an upper respiratory tract infection. It, therefore, stands to reason that COVID-19 could be causing anosmia,” Dr. Leigh Sowerby, associate scientist at Lawson and associate professor at Western University, said in a statement. “Colleagues in the United Kingdom first made note of this with a surge of patients presenting with sudden loss of smell and many of these patients went on to develop COVID-19.”

The survey, which is available in ten languages, asks participants about their experiences with COVID-19 and other respiratory illnesses. Through those answers, the researchers from 30 different countries hope to determine whether loss of smell is the same in symptomatic and asymptomatic patients. If the lost sense turns out to be an early warning sign of COVID-19 it would allow for earlier self-isolation measures.

There are existing therapies to regain a sense of smell, but it is unknown whether they will work for COVID-19 patients.

“We don’t yet know the long-term consequences of anosmia in COVID-19 patients and that’s why this research is important,” said Sowerby, who is also an Otolaryngologist at St. Joseph’s Health Care London. “[Smell] really is the forgotten sense; we don’t appreciate smell until it’s gone.”

The survey is available at