Small fiber neuropathy following COVID-19 vaccination: A case series

Various peripheral neuropathies, from facial palsy to Guillain-Barre Syndrome, following vaccination have been reported in several different vaccination contexts. However, the relation between small fiber neuropathy and vaccination is still unclear. In the context of COVID-19 vaccination it is even more difficult to assess a secure causality due to the short time that has elapsed since the vaccination, thus research on possible pathophysiology is still in progress. Nonetheless, due to the extensive vaccination campaign held for COVID-19 since 2021, we were able to collect and describe clinical and electrophysiological data of 16 patients with suspected small fiber neuropathy following vaccination, of which 9 fulfilled the criteria for diagnosis of SFN. Defining the causality is arduous, but temporality, analogies with other vaccinations and/or infections support our hypothesis. We underline the importance of post-marketing surveillance to detect rare adverse effects and consequently tailor future studies.