SFN symptoms resolved after treatment for Lyme Disease

An 83-year old woman had a four year history of diffuse burning pain in her face, arms, and legs, and muscle spasms in the legs. A blood test was positive for Lyme according to the CDC definition. Her symptoms resolved after treatment with antibiotics.

One surprise is that her symptoms went away even though repeat skin biopsy at 5 months post treatment revealed persistently low epidermal and sweat gland nerve fiber densities (!).

Known causes of SFN include toxic, metabolic, infectious, autoimmune, paraneoplastic, and
genetic causes. In 50% of cases the cause remains elusive (according to this paper on Coxsackie and Influenza viruses causing length-dependent SFPN).