London researchers join global initiative to study loss of smell in COVID-19 patients

As part of an initiative called the Global Consortium for Chemosensory Research (GCCR), scientists at Lawson Health Research Institute and Western University are studying the sudden loss of smell in COVID-19 patients. They are asking individuals with confirmed or presumptive cases of COVID-19 worldwide to participate in a survey to better understand this symptom.

A sudden loss of smell, called anosmia, has been widely reported as a marker of COVID-19. More research is needed but emerging evidence suggests that more than 60 per cent of COVID-19 patients experience anosmia and that it is often the first symptom of the disease. 

“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,” says Dr. Leigh Sowerby, Associate Scientist at Lawson and Associate Professor at Western University’s Schulich School of Medicine & Dentistry. “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.”

In the new study, patients with loss of smell will answer questions through a publicly accessible survey. They will be asked about their experiences with COVID-19 and other respiratory illnesses. An immediate goal is to better understand the association between anosmia and COVID-19, and determine if loss of smell is the same in symptomatic and asymptomatic patients. The team also hopes to determine if loss of smell happens before other symptoms of COVID-19 as it could allow for earlier self-isolation advice.

“As a sinus surgeon, I see many patients who have lost their sense of smell. It really is the forgotten sense; we don’t appreciate smell until it’s gone,” explains Dr. Sowerby, who is also an Otolaryngologist at St. Joseph’s Health Care London. “Smell is a very important part of taste. Imagine if all food tasted like cardboard, and all you could do was make that cardboard taste spicy, salty, sweet or bitter. It can also be a safety concern if you cannot smell a gas leak, burning food or smoke.”

While there are existing therapies that can aid in regaining a sense of smell, it’s currently unknown whether they are effective 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,” adds Dr. Sowerby. “I encourage anyone who has been diagnosed with COVID-19 or another respiratory illness to complete our survey if able.”

The GCCR survey is currently available in 10 languages at