Subcutaneous botulinum toxin-A injection for treating postherpetic neuralgia.

Postherpetic neuralgia (PHN) is a debilitating disease characterized by continuous, intense pain following an outbreak of herpes zoster. The pain associated with PHN can severely affect a patient's quality of life, quality of sleep, and ability to participate in activities of daily living. The aim of this study was to explore the clinical efficacy of the subcutaneous injection of botulinum toxin-A (BTX-A) for the treatment of PHN. Thirteen patients with PHN were enrolled in this study and treated once with BTX-A. The effects of BTX-A on pain were measured with the visual analogue scale (VAS) 1, 2, 4, 8, 12, and 16 weeks after administration. Compared with pretreatment scores, VAS pain scores decreased at 2 weeks post-treatment in all patients. All patients felt varying degrees of pain relief but remained comfortable. Compared with oral analgesic drugs, VAS scores were significantly different at 2, 4, 8, 12, and 16 weeks post-treatment (p < .05). These results demonstrated that subcutaneous administration of BTX-A can decrease pain in patients with PHN.