Loss of smell may be a symptom of coronavirus, doctors warn
While every case is different, the telltale symptoms of the novel coronavirus have been widely agreed upon - a fever, persistent cough or shortness of breath. In the most severe instances, those afflicted have reported confusion or difficulty breathing, and sometimes, anxiety is the most prevailing symptom of all.
But a team of British ear, nose and throat doctors on Friday raised the possibility of a new indicator of the coronavirus, one they say has been observed globally, even in patients who are otherwise asymptomatic: anosmia, a condition that causes the loss of sense of smell. In a statement, they warned that adults experiencing recent anosmia could be unknown carriers of covid-19, the disease caused by the novel coronavirus.
"All of this evidence is accumulating very rapidly, but there's nothing yet robustly in print," Claire Hopkins, president of the British Rhinological Society, said in an interview. "Since then, I've had colleagues from around the world saying: 'That's exactly what we're seeing.' They've been trying [to raise awareness], but it hasn't been picked up."
Experts at the World Health Organization say they have not confirmed that loss of smell or taste is a symptom of the coronavirus, but they have n0t ruled it out.
Hopkins, who published the statement along with Nirmal Kumar, the president of ENT UK, a body that represents, ear, nose and throat specialists in Britain, said she was driven by recent discussions on rhinological discussion boards related to the coronavirus pandemic. There, she observed ENT UK's reporting a surge of reported anosmia across their patients, and even among themselves.
In their statement, Hopkins and Kumar cited reports from South Korea, China, Iran and Italy, where, they wrote, "significant numbers of patients with proven covid-19 infection have developed anosmia/hyposmia," the latter of which signals a reduced ability to detect smells. In Germany, they wrote, more than two-thirds of confirmed coronavirus cases included anosmia. And in South Korea, a country that has seen ample covid-19 testing, "30 percent of patients testing positive have had anosmia as their major presenting symptom in otherwise mild cases."
"This week, I saw nine patients that lost their sense of smell, which is unheard of in my practice," Hopkins said. "They were almost all under 40, and they were all told not to self-isolate."
Anosmia and hyposmia are historically linked to early symptoms of upper-respiratory infections - including previous strains of coronavirus - because the virus damages olfactory bulbs that are involved in the sense of smell. But Hopkins raised concern at the number of covid-19 patients who were otherwise asymptomatic. She pointed to guidance in the United States and Britain that instructs people to self-isolate if they are experiencing obvious coronavirus symptoms.
Hopkins said she hopes that flagging another potential system will resonate with those who haven't taken social distancing and self-isolation seriously enough - the ones who do not realize they may carry the virus.
"The lack of awareness allows these people to carry on," she added. "This potentially gives us an opportunity to capture some of those people who are silent spreaders of disease. The patients I'm seeing haven't had a cough or fever at all."
Citing the ENT UK statement, the American Academy of Otolaryngology on Sunday wrote that in the absence of allergies, sinusitis or rhinitis, the loss of smell or taste should "warrant serious consideration for self-isolation and testing."