Chronic neuralgia incidence following local anesthetic therapy for herpes zoster.

We treated 72 patients, referred to a pain clinic for acute herpes zoster neuralgia, with local anesthetics administered by nerve block and infiltration. Only those patients with severe pain initially proved to be at risk for the development of chronic postherpetic neuralgia (defined as pain in the involved dermatomes lasting at least six months). Although local anesthetic injections effectively relieved the acute pain of active herpes zoster, they did not prevent the development of chronic postherpetic neuralgia.