Acute pain in herpes zoster: the famciclovir database project

The results of a considerable number of recent prospective studies have demonstrated that greater acute pain severity in herpes zoster patients is associated with a significantly greater risk of developing postherpetic neuralgia (PHN). Only a few studies have examined the relationships between acute pain severity and demographic characteristics and clinical features of patients with herpes zoster, however, and the results of these studies have been inconsistent. To clarify these relationships, data from 1778 herpes zoster patients studied within 72 h of rash onset in four clinical trials of the antiviral agent famciclovir were examined. Univariate and multivariate analyses indicated that greater acute pain severity was significantly associated with greater age, female sex, greater rash severity, the presence of a prodrome, and primary involvement of non-trigeminal dermatomes. These results demonstrate that three of the established risk factors for PHN - older age, greater rash severity, and the presence of a prodrome - are also associated with more severe acute pain assessed soon after rash onset in patients with herpes zoster. The results of this study are consistent with the recommendation that herpes zoster patients who are older, who have had a prodrome, or who have severe rash or severe acute pain should be targeted for interventions designed to prevent PHN.