‘Overwhelming’ Need to Study COVID Vaccine-Associated Tinnitus – Medscape
Editor’s note: Find the latest COVID-19 news and guidance in Medscape’s Coronavirus Resource Center.
It’s now known that tinnitus may be an unexpected side effect of SARS-CoV-2 vaccination, and there is an urgent need to understand the precise mechanisms and best treatment for vaccine-associated tinnitus, researchers say.
As of mid-September 2021, 12,247 cases of tinnitus, or ringing in the ears, following COVID-19 vaccination have been reported …….
Editor’s note: Find the latest COVID-19 news and guidance in Medscape’s Coronavirus Resource Center.
It’s now known that tinnitus may be an unexpected side effect of SARS-CoV-2 vaccination, and there is an urgent need to understand the precise mechanisms and best treatment for vaccine-associated tinnitus, researchers say.
As of mid-September 2021, 12,247 cases of tinnitus, or ringing in the ears, following COVID-19 vaccination have been reported to the Vaccine Adverse Event Reporting System of the US Centers for Disease Control and Prevention.
“Despite several cases of tinnitus being reported following SARS-CoV-2 vaccination, the precise pathophysiology is still not clear,” write Syed Hassan Ahmed, third-year MBBS student, Dow University of Health Sciences, Karachi, Pakistan, and co-authors.
The researchers review what is known and unknown about SARS-CoV-2 vaccine-associated tinnitus in an article published online February 11 in Annals of Medicine and Surgery.
Molecular Mimicry?
The researchers say cross-reactivity between anti-spike SARS-CoV-2 antibodies and otologic antigens is one possibility, based on the mechanisms behind other COVID-19 vaccine-induced disorders and the phenomenon of molecular mimicry.
“The heptapeptide resemblance between coronavirus spike glycoprotein and numerous human proteins further supports molecular mimicry as a potential mechanism behind such vaccine-induced disorders,” they write.
Anti-spike antibodies may react with antigens anywhere along the auditory pathway and fuel an inflammatory reaction, they point out.
“Therefore, understanding the phenomenon of cross-reactivity and molecular mimicry may be helpful in postulating potential treatment behind not only tinnitus but also the rare events of vaccination associated hearing loss and other otologic manifestations,” the authors say.
Genetic predispositions and associated conditions may also play a significant role in determining whether an individual develops vaccine-induced tinnitus.
Stress and anxiety following COVID vaccination may also play a role, inasmuch as anxiety-related adverse events following vaccination have been reported. Vaccine-related anxiety as a potential cause of tinnitus developing after vaccination needs to be explored, they write.
Jury Out on Best Management
How best to manage COVID vaccine-associated tinnitus also remains unclear, but it starts with a well-established diagnosis, the authors say.
A well-focused and detailed history and examination are essential, with particular emphasis placed on preexisting health conditions, specifically, autoimmune diseases, such as Hashimoto thyroiditis; otologic conditions, such as sensorineural hearing loss; glaucoma; and psychological well-being. According to the review, patients often present with a history of one or more of these disorders.
“However, any such association has not yet been established and requires further investigation to be concluded as potential risk factors for vaccine-induced tinnitus,” they caution.
Routine cranial nerve examination, otoscopy, Weber test, and Rinne test, which are used for tinnitus diagnosis in general, may be helpful for confirmation of vaccine-associated tinnitus.
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