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.” 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.” 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. 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. Hyperviscosity is reported as cause of facial palsy in the literature and might be another cause of reported syndrome in the case report.