Small Fiber Neuropathy Associated with SARS-CoV-2 Infection

Abstract Introduction/Aims The development and persistence of neurological symptoms following SARS-CoV-2 infection is referred to as ?long-haul? syndrome. We aimed to determine whether small fiber neuropathy (SFN) was associated with SARS-CoV-2 infection. Methods We retrospectively studied the clinical features and outcomes of patients who were referred to us between May 2020 and May 2021 for painful paresthesia and numbness that developed during or after SARS-CoV-2 infection and who had nerve conduction studies showing no evidence of a large fiber polyneuropathy. Results We identified 13 patients, 8 women and 5 men with age ranging from 38-67?years. Follow-up duration ranged from 8 to 12 months. All patients developed new-onset paresthesias within 2 months following SARS-CoV-2 infection, with an acute onset in 7 and co-existing autonomic symptoms in 7. Three patients had pre-existing but controlled neuropathy risk factors. Skin biopsy confirmed SFN in 6, all of whom showed both neuropathy symptoms and signs, and 2 also showed autonomic dysfunction by autonomic function testing (AFT). Of the remaining 7 patients who had normal skin biopsies, 6 showed no clinical neuropathy signs and 1 exhibited signs and had abnormal AFT. Two patients with markedly reduced intraepidermal nerve fiber densities and 1 with normal skin biopsy had severe and moderate COVID-19;the remainder experienced mild COVID-19 symptoms. Nine patients received symptomatic neuropathy treatment with paresthesias controlled in 7 (77.8%). Discussion Our findings suggest that symptoms of SFN may develop during or shortly after COVID-19. SFN may underlie the paresthesias associated with long-haul post-COVID-19 symptoms.