Single paravertebral injection for acute thoracic herpes zoster: a randomized controlled trial.

BACKGROUND: The aim of this study was to evaluate the efficacy of single thoracic paravertebral injection in acute thoracic herpes zoster (HZ) pain, eruptive duration, and the incidence of postherpetic neuralgia (PHN).

METHODS: One hundred thirty-eight patients over 50 years of age with acute thoracic herpetic eruption were randomly assigned to receive a paravertebral block using either 10 mL saline (placebo group) or 25 mg bupivacaine, plus 8 mg dexamethasone in a total volume of 10 mL (active group). All the patients received pregabalin 150 mg twice daily. Acetaminophen was available as rescue analgesia. Pain severity was assessed using visual analog scale (VAS). Analgesics consumption was evaluated weekly. Time to pain resolution, healing of the skin eruption, and incidence of persistent postherpetic pain were reported.

RESULTS: Significantly shorter duration of pain and herpetic eruption was noticed in the active group vs. placebo group (P = 0.013 and < 0.001, respectively). Active group showed significantly lower VAS at the third week. Significantly lower doses of pregabalin and acetaminophen were consumed in the active group. Incidence of PHN was comparable in both groups after 3 months (P = 0.094). A significantly lower incidence of PHN was noted in active treatment group at 6 months (P = 0.048).

CONCLUSION: Early single paravertebral blockade in the course of acute thoracic HZ seems to be a safe and effective adjuvant treatment modality.