Ramsay Hunt syndrome and mRNA SARS-COV-2 vaccination

Dear Editor:

We would like to share ideas on “Ramsay Hunt syndrome following mRNA SARS-COV-2 vaccine.¹” Rodríguez-Martín et al. noted that “The onset of ocular symptoms starting within one week following vaccination suggests an inflammatory or autoimmune … Ophthalmologists should consider the option of autoimmune … as uveitis, following COVID-19 vaccination.¹” In general, adverse reaction to new COVID-19 is sporadically reported. The facial palsy is also possible. For Ramsay Hunt syndrome, there are many possible causes. In the present case, BNT162b2 vaccine is used. For mRNA COVID-19 vaccine, the important consideration is on induction of autoimmunity. Association between autoimmunity and Ramsay Hunt syndrome is reported.² Nevertheless, if the autoimmunity is the cause of post COVID-19 vaccination Ramsay Hunt syndrome, an abnormal autoimmunity should be detected. The other possible cause of facial palsy after COVID-19 vaccination is the vaccine induced hyperviscosity. After receiving COVID-19 vaccine, a recipient might develop excessive immune response and result in excessive blood viscosity.³ Hyperviscosity is reported as cause of facial palsy in the literature and might be another cause of reported syndrome in the case report.⁴