COVID Arm and COVID Toe have already been formally identified by the medical community as side effects from COVID-19 and its associated vaccines. Now COVID Ear is here to tick off one more body part in the Heads, Shoulders, Knees And Toes nature of COVID complications.
Auditory disturbances such as hearing loss and tinnitus (ringing in the ears) have been reported by people infected with SARS-CoV-2, the pathogen that causes the disease COVID-19. It’s also been associated with difficulties in balance, something that can happen when things go wrong in our ears.
COVID Ear study
To investigate if COVID-19 really is messing with our sound flaps, a new paper published in the journal Communications Medicine looked at 10 COVID-19 patients with ear troubles.
Based on insights gleaned from looking in their ears and those of mice, they were able to run the first in vitro cellular models of infectious inner ear disease to try and establish a mechanism for COVID-19 infecting and affecting the ear and ear canal.
Their result showed that our ear tissue is home to something called an ACE2 receptor, a recognized entry point for the SARS-CoV-2 pathogen. They also come complete with TMPRSS2 and FURIN, two cofactors needed for successful virus entry. Great.
Our ears also have Schwann cells, which might sound like Sean Connery saying swan but are in fact another variety of human flake that SARS-CoV-2 is fond of. Add to that the fuzzy nature of our ears, whose hair cells have proved to be another point of entry for the pathogen, and the ear is starting to look like a pretty suss place for COVID-19.
“We show that human and mouse inner ear cells have the molecular machinery to allow SARS-CoV-2 entry,” wrote the study authors. “We further show that SARS-CoV-2 can infect specific human inner ear cell types. Our findings suggest that inner ear infection may underlie COVID-19-associated problems with hearing and balance.”
Symptoms of COVID Ear
So, what can COVID Ear sufferers expect to experience? The study only looked at 10 patients, which isn’t a big enough sample size to generalize from. However, for this group the associated symptoms of COVID Ear were pretty similar, including hearing loss that ranged from profound to moderate, tinnitus, and vertigo, a fancy word for dizziness.
How COVID Ear develops
As for how these symptoms emerge, the study identified three routes through which COVID-19 ear damage could occur. Route one infects and kills cochlear hair cells which are instrumental in hearing. Route two infects and kills vestibular hair cells, tiny hairs that detect changes in movement such as turning your head, speeding up, or slowing down. And finally, route three gets us in the primary afferent auditory and/or vestibular nerve cells. Two cells that report back to our brains.
The long and short of it: it’s not a great time to be sharing in-ear headphones.