Reader Response: Intravenous Immunoglobulin Therapy in Patients With Painful Idiopathic Small Fiber Neuropathy.

Geerts et al.1 showed, in a randomized controlled trial, that intravenous immunoglobulin (IVIg) has no significant effect on pain in patients with painful idiopathic small fiber neuropathy (SFN). A potential exception is represented by patients with idiopathic SFN with a nonlength-dependent (NLD) phenotype, as they were excluded by the design of the study.