Relationship Between Time of Treatment of Acute Herpes Zoster With Sympathetic Blockade and Prevention of Post-Herpetic Neuralgia: Clinical Support for a New Theory of the Mechanism by Which Sympathetic Blockade Provides Therapeutic Benefit

Abstract

Sympathetic blockade applied within the first 2 months after the onset of acute herpes zoster terminated the acute phase of the disease, probably by restoring intraneural blood flow, thus preventing the death of the large fibers and avoiding the development of post-herpetic neuralgia. If sympathetic blocks were to be carried out after 2 months, the damage to the large fibers would be irreversible, and this therapeutic modality would not be able to prevent the development of post-herpetic neuralgia.