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.