Medics have reported the first confirmed case of coronavirus-induced hearing loss in the UK.
An unnamed 45-year-old man spent 30 days on a ventilator after the infection left him struggling to breathe.
A week after leaving intensive care, he developed ringing in his left ear, followed by sudden hearing loss.
Tests revealed he had lost a “substantial” amount of hearing in that ear, which the University College London (UCL) medics put down to the coronavirus.
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The man’s hearing partially returned following a course of steroid tablets, however, the team described the damage as “irreversible”.
Although unclear exactly why this occurred, the coronavirus has been found in cells lining the middle ear, according to the medics.
The infection can also trigger inflammation and the release of chemicals that have been linked to hearing loss, they added.
“This is the first reported case of sensorineural [a lesion or disease of the inner ear or auditory nerve] hearing loss following COVID-19 infection in the UK,” the medics wrote in the BMJ Case Reports.
“Given the widespread presence of the virus in the population and the significant morbidity of hearing loss, it is important to investigate this further.”
After surveying 121 coronavirus survivors eight weeks after they were discharged from hospital, 16 (13.2%) complained their hearing was worse, of whom eight reported deterioration to the sense and another eight developed tinnitus – hearing ringing, whooshing or buzzing without an external source.
Hearing loss may be a symptom of long COVID, when a former coronavirus patient endures complications after testing negative for the infection.
Watch: What is long COVID?
Coronavirus aside, sudden hearing loss is relatively common, affecting up to 160 in every 100,000 people annually around the world.
Although the cause is often unclear, it has been linked to viral infections like flu or herpes.
Only a handful of coronavirus-related hearing loss cases had previously been reported, none of whom were in the UK.
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The UCL medics have since described how a man – who was healthy aside from having asthma – was admitted to hospital following 10 days of coronavirus symptoms.
While on a ventilator in intensive care, he developed several complications, including blood clots in the lungs, high blood pressure and anaemia.
The man gradually improved following treatment with the drug remdesivir, intravenous steroids and a blood transfusion.
A week after leaving intensive care, he developed tinnitus in his left ear.
The man was referred to an ear, nose and throat specialist when he lost all hearing in that ear.
An examination revealed no blockage or inflammation in his ear canals.
After testing negative for other potential causes – like rheumatoid arthritis, flu and HIV – the medics concluded the coronavirus was to blame.
“Physical examination and imaging excluded any other cause of hearing loss,” they wrote.
The man was prescribed a week’s worth of oral steroids, which “resulted in partial subjective improvement in his hearing”.
Three subsequent steroid injections “resulted in no further improvement in his hearing”.
The coronavirus is thought to enter cells by binding to the angiotensin-converting enzyme 2 (ACE2) receptor.
ACE2 is present in lung cells, with animal studies suggesting it is also in the middle ear.
Off the back of their case report, the UCL medics are encouraging other doctors to ask coronavirus patients in intensive care about their hearing.
Prompt steroid treatment may prevent any lasting damage, they added.
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