Shingles: Are You Risking Nerve Pain?
What Is Shingles and Postherpetic Neuralgia? continued...
For reasons that experts don't really understand, the pain of shingles lingers for some. If the pain lasts for at least 3 months after the shingles rash has healed, a person is diagnosed with PHN. In some people, the pain will subside. In others, it won't.
"We don't have any idea why the pain goes away in some people and not others," says Dworkin. But the longer you have PHN -- especially after a year -- the less likely it is to resolve, he says.
Risk Factors for Nerve Pain After Shingles
Researchers have long known that older people are more likely to get PHN, the nerve pain after shingles, but recent studies have found other factors that increase risks.
In one study published in the journal Neurology, researchers -- including Dworkin -- looked at data from 965 people with shingles. The researchers identified five risk factors for developing PHN in people who had been recently diagnosed with shingles:
- Presence of symptoms before the rash appeared, like numbness, tingling, itching, or pain
- Severe pain during the illness's initial stages
- Severe rash
Importantly, the researchers found the more risk factors you have, the greater the risk of developing PHN.
For instance, 17% of women with shingles and 26% of those who had severe pain went on to get PHN. But 50% of women who were over age 60 and had symptoms before the rash, severe rash, and acute pain went on to get PHN.
The Emotional Toll of Nerve Pain After Shingles
Researchers are not just looking at biological and neurological risk factors for PHN. Dworkin was also a co-author of a study looking at psychological risk factors, too. The results were published in the Journal of Pain in 2005.
"It certainly looks like psychological stress can be a potent risk factor for PHN," Dworkin tells WebMD.
The study showed that people with shingles who went on to develop PHN were more likely to have had symptoms of personality disorders, hypochondria, intense worry about their disease, and other bodily complaints.
Dworkin says previous studies have already shown a connection between stress and shingles development.
"One study even found that the risk of developing PHN was higher in people who were living alone when they developed shingles than people living with others," Dworkin says, perhaps indicating that social isolation increases the risks of PHN.