More than a few oral health problems have been linked to COVID: ulcers and other kinds of lesions, erosions, plaque, bad breath, swelling, and even necrosis. According to case reports and other medical communications, the tongue is the site affected most often, and cases are split pretty equally between men and women. However, oral symptoms are said to crop up more often in older adults and those with more severe cases of COVID.
Lack of oral hygiene, opportunistic infections, stress, immunosuppression, vasculitis, and hyper-inflammatory response secondary to COVID-19 are the most important predisposing factors for onset of oral lesions in COVID-19 patients.
One type of problem mentioned in the above study has recently received a bit of extra attention: geographic tongue.
Funny name, we know, but it’s a lot easier to pronounce than some of the other names this inflammatory condition goes by, such as erythema migrans or benign migratory glossitis.
It’s not exclusive to COVID patients, though. It’s something that turns up in anywhere from 1 to 3% of the population, and it makes areas of the tongue appear smooth and red, due to the loss of papillae (those little nubbly projections that normally cover the tongue’s surface). The contrast between these patches and other areas can look kind of like a map – hence, the name.
The causes of geographic tongue aren’t totally clear. Some of the candidates that have been suggested over the years include stress, parafunctional habits like tongue biting, allergies, and hormonal fluctuations. Although it can look kind of gross, the condition isn’t contagious and typically doesn’t even need to be treated, since there are seldom any symptoms beyond just the tongue’s appearance.
“If a [geographic tongue] is of recent onset, could it signify COVID-19?” asks Dr. Russell Hathway, of the department of oral and maxillofacial surgery at Morriston Hospital in Swansea, UK, in a recent letter to the BDJ. “Possibly.”
There is some evidence to suggest that GT might be associated with elevated levels of the inflammatory cytokine interleukin-6 (IL-6), the same cytokine that is upregulated in severe COVID-19 disease. It is also worthwhile remembering that angiotensin-converting enzyme 2 (ACE2) receptor expression is higher in the tongue relative to other oral tissues. ACE2 receptors are the entry point of the SARS-CoV-2 virus.
The suspected link, he notes, was identified via patient reports submitted daily to the ZOE COVID-19 Symptom Study app.
Professor Spector, the study’s lead researcher from King’s College London, has reported a number of user submissions that seem to be consistent with GT, but to date there are only two communications in the literature reporting it as part of COVID-19 illness.
Of course, much more research is needed to either confirm or disprove the link. And it can’t be emphasized enough that simply having geographic tongue doesn’t necessarily mean you have COVID.
But as Dr. Hathway’s letter suggests, if your tongue has only recently taken on this appearance, you may want to talk about it with your dentist or physician sooner rather than later. And the same goes with the appearance of any strange lesions or other changes in your mouth. The sooner we can identify the problem and its significance, the sooner we can work with you to go about solving it.
Image by Bin im Garten