This trial will test a treatment called Panzyga on patients with small fiber neuropathy (SFN). SFN patients often suffer from undiagnosed pain, and current treatments have many side effects. Panzyga may help by reducing inflammation and improving nerve function, potentially reducing pain and increasing nerve density in the skin. Panzyga has been shown to be effective in treating various autoimmune neurological disorders and has potential benefits for managing neuropathic pain.