Although uncommon, sudden permanent hearing loss seems to be linked to Covid-19 infection in some people, warn doctors, reporting the first UK case in the journal BMJ Case Reports.
Awareness of this possible side effect is important because a prompt course of steroid treatment can reverse this disabling condition, they emphasise.
Sudden hearing loss is frequently seen by ear, nose and throat specialists, with around five to 160 cases per 100,000 people reported every year.
It’s not clear what the causes are, but the condition can follow a viral infection, such as flu, herpes, or cytomegalovirus.
Despite plenty of published research on sudden onset hearing loss, only a handful of other cases associated with Covid-19 have been reported, and none in the UK until now.
The doctors describe a case of a 45-year-old man with asthma who was referred to the ear nose and throat department at their hospital after suddenly experiencing hearing loss in one ear while being treated for Covid-19 infection as an inpatient.
Examination of his ear canals revealed that he had no blockages or inflammation. But a hearing test showed that he had substantially lost his hearing in the left ear. He was treated with steroid tablets and injections after which his hearing partially recovered.
He tested negative for other potential causes, including rheumatoid arthritis, flu and HIV, prompting his doctors to conclude that his hearing loss was associated with a Covid-19 infection.
“Hearing loss and tinnitus are symptoms that have been seen in patients with both Covid-19 and influenza virus, but have not been highlighted,” say the report authors.
The first case of hearing loss mentioning Covid-19 alone was reported in April this year.
SARS-CoV-2, the virus responsible for Covid-19, is thought to lock on to a particular type of cell lining the lungs. And the virus has also recently been found in similar cells lining the middle ear, explain the report authors.
SARS-CoV-2 also generates an inflammatory response and an increase in the chemicals that have been linked to hearing loss.
To read the case report, visit: casereports.bmj.com/lookup/doi/10.1136/bcr-2020-238419