Shingles: Are you risking nerve pain?

If you have shingles symptoms, get treatment now and you may avoid permanent nerve pain.

Shingles, a viral infection of the nerve roots, affects 250,000 people in the UK each year. Most people recover from their bout, but for as many as 20% to 30% of them, the pain doesn't go away. It can last for months, years or even the rest of their lives.

These people have postherpetic neuralgia (PHN), the result when the shingles virus damages the nerves of the skin. In some cases the pain is mild. In others even the slightest touch - from clothing or even a breeze - can be excruciating.

"PHN causes a great deal of suffering and high social costs," says Robert Dworkin, a professor in the department of anesthetics at the University of Rochester Medical Center in the US. "It can severely disrupt people's lives."

But the good news is that there are drugs that can help treat and even prevent PHN, and doctors are learning more about who is at greatest risk of developing this debilitating condition.

Shingles and PHN: causes, symptoms and contagion

Shingles is caused by the varicella-zoster virus, the virus that also causes chickenpox. In a person who has been exposed to chickenpox - or its vaccine - the virus never really goes away. It can lie dormant in the body's nerves.

In most cases it stays that way. But in some - especially people with immune systems weakened by disease or treatment - the virus can reappear. This is likely to happen years or decades after the person had chickenpox.

When it comes back the virus can cause shingles: a rash that often appears as a band on one side of the body. Early shingles symptoms can include:

• Headache
• Light sensitivity
• Flu-like symptoms without fever

Itching, tingling,or extreme pain where the rash is developing may come next, and the pain can be moderate to severe.

Are you contagious? Though people who haven't had chickenpox can catch that condition from you, the shingles itself isn't contagious.

For reasons that experts don't really understand the pain of shingles lingers for some. If the pain lasts for at least four months after the shingles rash appeared, 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.