Management of herpes zoster (shingles) and postherpetic neuralgia

Herpes tester (commonly referred to as "shingles") and postherpetic neuralg ia result from reactivation of the varicella-zoster virus acquired during t he primary varicella infection, or chickenpox. Whereas varicella is general ly a disease of childhood, herpes tester and postherpetic neuralgia become more common with increasing age. Factors that decrease immune function, suc h as human immunodeficiency virus infection, chemotherapy, malignancies and chronic corticosteroid use, may also increase the risk of developing herpe s tester. Reactivation of latent varicella-zoster virus from dorsal root ga nglia is responsible for the classic dermatomal rash and pain that occur wi th herpes tester. Burning pain typically precedes the rash by several days and can persist for several months after the rash resolves. With postherpet ic neuralgia, a complication of herpes tester, pain may persist well after resolution of the rash and can be highly debilitating. Herpes tester is usu ally treated with orally administered acyclovir. Other antiviral medication s include famciclovir and valacyclovir. The antiviral medications are most effective when started within 72 hours after the onset of the rash. The add ition of an orally administered corticesteroid can provide modest benefits in reducing the pain of herpes tester and the incidence of postherpetic neu ralgia. Ocular involvement in herpes tester can lead to rare but serious co mplications and generally merits referral to an ophthalmologist. Patients w ith postherpetic neuralgia may require narcotics for adequate pain control. Tricyclic antidepressants or anticonvulsants, often given in low dosages, may help to control neuropathic pain. Capsaicin, lidocaine patches and nerv e blocks can also be used in selected patients.