Do corticosteroids prevent postherpetic neuralgia? A review of the evidence.

A short course of corticosteroids is frequently used in herpes zoster to prevent postherpetic neuralgia. To clarify the evidence behind this routine practice, we reviewed the three randomized controlled trials on this subject. Although in all three similar dosages of corticosteroids (40 mg to 60 mg prednisone daily for 2 to 4 weeks) were used, deficiencies in reported clinical characteristics of study subjects, the potential for bias in the ascertainment of pain duration, and the inability to exclude type II error make it impossible to determine whether or not this practice is effective. More research on this subject is needed, with greater attention to good study methodology.