March 23, 2020
What is known about the coronavirus changes every day as doctors gather data from the front lines of this public health emergency.
Recently, there have been reports that COVID-19 includes digestive symptoms like diarrhea, and now the American Academy of Otolaryngology-Head and Neck Surgery is saying that the loss of sense of smell and taste may also be indicators of this viral infection.
These doctors are asking that loss of sense of smell – medically known as anosmia – and loss of taste – known as dysgeusia – be added to the potential symptoms checked during COVID-19 screenings. Even hyposmia – the reduced ability to smell – could suggest a COVID-19 infection, AAO-HNS doctors say.
"Anosmia, in particular, has been seen in patients ultimately testing positive for the coronavirus with no other symptoms," according to the statement posted Sunday to the AAO-HNS website.
The statement continued to read that, "Anosmia, hyposmia and dysgeusia in the absence of other respiratory disease such as allergic rhinitis, acute rhinosinusitis, or chronic rhinosinusitis should alert physicians to the possibility of COVID-19 infection and warrant serious consideration for self-isolation and testing of these individuals."
ENT UK, a professional organization of ear, nose and throat surgeons in the United Kingdom has also made its own statement about the anecdotal evidence coming out coronavirus hotspots.
"There is already good evidence from South Korea, China and Italy that significant numbers of patients with proven COVID-19 infection have developed anosmia," the British doctors said.
"In Germany it is reported that more than 2 in 3 confirmed cases have anosmia. In South Korea, where testing has been more widespread, 30% of patients testing positive have had anosmia as their major presenting symptom in otherwise mild cases."
They added that Iran, the U.S., France and Northern Italy have all seen an increase of cases where the only symptom is the loss of smell and that these patients may be hidden carriers of the novel coronavirus.
Anosmia has long been associated with respiratory infections. "Viruses that give rise to the common cold are well known to cause post-infectious loss, and over 200 different viruses are known to cause upper respiratory tract infections," the ENT UK surgeons said.
"Previously described coronaviruses are thought to account for 10-15% of cases. It is therefore perhaps no surprise that the novel COVID-19 virus would also cause anosmia in infected patients."
Not all health experts, however, agree that the loss of smell or taste should be added to screening criteria at this time.
Philadelphia Health Commissioner Dr. Thomas Farley said Monday that the city would not expand the symptoms requirements at its South Philly testing site to include loss of smell or taste.
"I think that's very nonspecific, can happen with other illnesses and may not be characteristic of this," Farley said. "So we will not be looking at that. "
Farley could not provide the prevalence of such symptoms among Philly's coronavirus cases.
"It's not something that we collect information on, so I can't give you an answer," Farley said.
Smell and taste disorders are diagnosed and treated by an otolaryngologist or ear, nose, throat, head and neck (ENT) specialist. Lack of smell can be tested by measuring the smallest amount of odor a person can smell or by using a paper booklet filled with beads with different odors. Patients are asked to identify each odor.
"Sip, spit, and rinse," tests where chemicals are applied to the tongue are often used to diagnose taste disorders, according to Johns Hopkins Medicine.