The effects of epidural blockade on the acute pain in herpes zoster

Objective: To evaluate the relief of acute pain and possible preventive effects on postherpetic neuralgia through the use of an epidural blockade in the acute stage of herpes zoster. Design: Prospective, nonrandomized, comparative clinical trial. Setting: A dermatologic clinic in a university hospital. Patients: Sixty-five consecutive patients with pain due to acute herpes zoster were treated for a 7-day hospitalization period from July 1, 1996, through June 30, 1997. Intervention: The consecutive patients were divided into 2 groups. Group A consisted of 30 patients who were seen from July 1, 1996, through December 31, 1996, and who were treated with intravenous acyclovir (5 mg/kg) for 7 days. Group B consisted of 35 patients who were seen from January 1, 1997, through June 30, 1997, and who were treated with intravenous acyclovir (5 mg/kg) and an epidural blockade for 7 days. The changes in the intensity of pain and the total duration of pain in both groups were assessed for 12 to 18 months. Main Outcome Measures: The number of days required for relief of pain and the total duration of pain. Results: The mean ± SD number of days required for relief of pain, which was rated on a scale of 100 (worst pain) to 0 (no pain), was significantly fewer in group B than in group A: it took 2.6 ± 1.1 days to go from 100 to 50 on- the relief-of-pain scale in group B, but 3.8 ± 1.1 days in group A (P = .03), and 12.5 ± 6.4 days to go from 100 to 10 in group B, but 20.1 ± 14.6 days in group A (P = .04). The duration of late residual pain was significantly shorter in group B (5.9 ± 5.8 days) than in group A (11.9 ± 7.5 days) (P = .03). The total duration of pain was also significantly shorter in group B (18.5 ± 9.3 days) than in group A (31.6 ± 17.6 days) (P = .04). Conclusions: We believe that an epidural blockade combined with an antiviral agent is a very effective treatment modality for the pain of acute herpes zoster, and we recommend its use for the prevention of postherpetic neuralgia, with a view to shortening the total duration of pain, especially late residual pain.