Shingles and Postherpetic Neuralgia: What Are the Risk Factors? continued...
The risk of postherpetic neuralgia also 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 Ralph.
The results of one study showed that age had a huge effect on the risk for postherpetic neuralgia after shingles:
- Among people under 60 years old who had shingles, less than one in 50 developed postherpetic neuralgia.
- In people aged 60 to 69, about 7% of shingles sufferers developed postherpetic neuralgia.
- In those age 70 and older, almost 20% developed postherpetic neuralgia after a bout of shingles.
Race seems to matter, too. 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.
Exposure to someone with chickenpox or shingles does not increase your personal risk, however. In fact, experts believe that the slight immune stimulation may boost natural defenses, making you less likely to develop shingles or PHN.
Vaccine Prevention for Shingles and Postherpetic Neuralgia
In 2006, a vaccine to prevent shingles came onto the market. Called Zostavax, the vaccine cuts the likelihood of getting shingles after chickenpox by about half, dramatically reducing the number of people who might get nerve pain after shingles.
Based on these results, the CDC recommends Zostavax to all adults age 60 and older. Rumbaugh goes further: He suggests you get vaccinated at any age if you have had shingles. His clinical experience suggests the vaccine helps reduce postherpetic neuralgia even after infection with the varicella zoster virus.
Early Intervention Is the Key to Treatment
Antiviral medicines such as valacyclovir ( Valtrex), famciclovir ( Famvir) or acyclovir ( Zovirax), taken orally, are usually used to treat shingles. When taken at the very beginning, Ralph says, they can improve symptoms and reduce the risk of postherpetic neuralgia.
Starting antiviral treatment for shingles more than three days after symptoms start is generally believed to be ineffective because the virus is no longer reproducing. Still, many doctors will try treating the condition with antiviral drugs after this time.