fully 99. 5% of adults in the u. s. carry the shingles virus. one-third of those people get shingles and some of them go on to develop postherpetic neuralgia. the risk of postherpetic neuralgia goes up with age. more than 80% of cases of postherpetic neuralgia occur in people over 50 years old. "it's likely that the natural decline of immunity with age is responsible " says jeffrey ralph md assistant professor of neurology at the university of california san francisco and a fellow of the neuropathy association. for unknown reasons white americans get shingles and postherpetic neuralgia at more than twice the rate of african-americans in their age group. "people whose immune systems are impaired by drugs or diseases like aids are also more prone to zoster and phn " adds ralph.
what are the risk factors for shingles and postherpetic neuralgia?