Fever, a cough, fatigue — at this point you can probably recite the symptoms of COVID-19 in your sleep. But even as the pandemic nears the year mark, a new, puzzling possible symptom has emerged: COVID tongue. Professor Tim Spector, an epidemiologist from King's College London, tweeted in January that COVID-positive patients were emailing him with strange oral symptoms, including inflamed, discolored tongues, and sores in their mouths. And while it may seem counterintuitive that a respiratory virus could make your tongue weird, experts tell Bustle COVID tongue isn't all that out there.
"We know that SARS COV-2 triggers a variety of diffuse inflammation and clotting reactions throughout the body, so it is not surprising that the presence of mouth sores has been documented," Dr. Kathleen Jordan M.D., SVP of Medical Affairs at women’s health provider Tia, tells Bustle. She explains that a lot of things can cause inflammation that breaks down the epithelial lining — that inner layer of skin — in your mouth, and causes an open sore prone to infection and pain. Herpes, infections, and canker sores are all common culprits. COVID might now be joining that list.
A study in British Journal of Dermatology in September 2020 found that, out of 666 patients, over 25% had some kind of symptom in their mouth or tongue, including swollen lumps on the tongue, scalloping at the tongue's edges, or burning sensations. And a June 2020 study in Evidence-Based Dentistry suggested a link between COVID and painful mouth blisters.
Professor Spector, who leads the UK arm of the crowd-sourced ZOE COVID Symptom study, told TODAY that COVID tongue can show up as a furry coating on the tongue surface. Why? “The tongue contains a high concentration of a protein called angiotensin converting enzyme 2 (ACE2)," Dr. Omid Mehdizadeh M.D., an otolaryngologist at Providence Saint John's Health Center, explains. "It's been found to be a primary attachment site for the COVID-19 virus." The virus enters cells via attachment sites, using them as gateways. Because there's a lot of this protein on the tongue, the COVID virus might show up there in droves — and make your tongue look like a fuzzy bath mat.
COVID tongue isn't on the World Health Organization's official list of symptoms, and it's also not used to diagnose COVID. "Tongue lesions, or ulcers, are not a typical classic indication of COVID-19, and are very nonspecific with many possible causes," Dr. Jordan says. "One should not assume that you have COVID if you have a mouth sore." One study in the Journal of Infectious Diseases in August 2020 suggested that, for a lot of people, mouth ulcers might be side effects of the battering that COVID gives the immune system, rather than symptoms themselves. This kind of tongue weirdness can also be caused by mouth infections like oral thrush, dehydration, or antibiotics.
If you suddenly develop a swollen tongue or a strange sore in your mouth, Dr. Jordan recommends keeping the sore area clean with medical rinsing. If there's the faintest possibility you might have COVID-19, she says, you should get tested and quarantine until your results come back negative.
Dr. Kathleen Jordan M.D.
Dr. Omid Mehdizadeh M.D.
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