Herpes zoster and postherpetic neuralgia: prevention and management.

Herpes zoster (shingles) is diagnosed clinically by recognition of the distinctive, painful vesicular rash appearing in a unilateral, dermatomal distribution. An estimated 1 million cases occur in the United States each year, and increasing age is the primary risk factor. Laboratory testing, including polymerase chain reaction, can confirm atypical cases. Treatment with acyclovir, famciclovir, or valacyclovir decreases the duration of the rash. Adjunct medications, including opioid analgesics, tricyclic antidepressants, or corticosteroids, may relieve the pain associated with acute herpes zoster. There is conflicting evidence that antiviral therapy during the acute phase prevents postherpetic neuralgia. Postherpetic neuralgia in the cutaneous nerve distribution may last from 30 days to more than six months after the lesions have healed. Evidence supports treating postherpetic neuralgia with tricyclic antidepressants, gabapentin, pregabalin, long-acting opioids, or tramadol; moderate evidence supports the use of capsaicin cream or a lidocaine patch as a second-line agent. Immunization to prevent herpes zoster and postherpetic neuralgia is recommended for most adults 60 years and older.