From the WebMD Archives

Sept. 4, 2018 -- In May 2015, Jackie Shelton, a public relations professional and mother of two in Reno, NV, noticed a rash on the back of her leg. She'd been working in her yard and thought nothing of it. Then she awoke in the middle of the night in excruciating pain.

"The pain was emanating from inside my leg and radiating up to the surface," she says. "It was like fire ants inside my body, on my nerves."

A trip to urgent care led to an unexpected diagnosis: She had shingles.

Shelton was 50 years old. At the time, she was considered 10 years too young to get the Zostavax shingles vaccine, which was recommended for people ages 60 and older.

"I had really not paid any attention to shingles until I found out I had it. Everything I read said it affected older people, so that was a surprise," she says.

Katie Ochoa was just 28 when she got the telltale rash. "I called the doctor's office and said, 'I think I have shingles.' They laughed and said, 'You don't have shingles.' As soon as I pulled up my shirt they were like, 'Wow, this is shingles.' "

Shingles is known as a disease that mainly strikes older adults, because the varicella zoster virus that causes it often emerges from its slumber late in life. Varicella is the same virus responsible for chickenpox. After you recover from chickenpox in childhood, the virus lies dormant in your nerve cells. It can reawaken as the painful, blistering shingles rash when your immune system naturally weakens with age.

Over the last 6 decades, there has been a steady uptick in the number of shingles cases in the United States -- even among younger adults. A 2016 study found that rates of shingles have been climbing since the mid-1940s in all age groups. From 1945 to 1949, 0.76 out of every 1,000 people got the disease. Between 2000 and 2007, that number rose to 3.15 people per 1,000.

The virus has hit older adults particularly hard. Shingles rates rose 39% from 1992 to 2010 in people over 65.

What's behind the increase in shingles cases? Researchers have a few theories.

The Chickenpox Vaccine

Before the chickenpox vaccine was introduced in the mid-1990s, almost everyone in the United States came down with this bumpy, itchy rash. Since then, the number of chickenpox cases has dropped by 90%.

The lack of circulating chickenpox virus could actually be a problem when it comes to shingles.

In the 1960s, English doctor and epidemiologist Edgar Hope-Simpson proposed the idea that being exposed to chickenpox helps boost the immune system response against the virus. In other words, when you're around people with the virus, your immune system stays armed and ready to prevent it from reawakening in your body.

"If what Hope-Simpson said was correct, that opens the possibility that if you reduce exposures to kids with chickenpox, it might mean that kids are getting less of this exogenous [external] boosting. That might put them at greater risk for shingles, and at a younger age," says Rafael Harpaz, MD, a CDC medical epidemiologist who has been studying the shingles virus for 15 years.

It’s also possible that the chickenpox vaccine itself might cause shingles, because it contains a live but weakened form of the virus.  But Harpaz says that risk is likely very small.

A 2013 study Harpaz co-wrote seemed to quash the link between the chickenpox vaccine and shingles. It revealed that shingles rates started to rise long before the vaccine came out. Although he says the issue is complicated, "There has been no evidence that there was an increase in shingles after the vaccine was introduced."

Other Theories

If the chickenpox vaccine isn't to blame, what is behind the rise in shingles cases? One possibility researchers have studied is a rise in the number of people who are living with immune system-weakening diseases like HIV and cancer, which can make shingles more likely. But while the number of people living with a suppressed immune system has risen, Harpaz has found that shingles has also increased among people with healthy immunity.

Another possibility is that higher rates of chronic diseases like diabetes and heart disease may have contributed to shingles risk. Again, Harpaz and his team studied this, and "We basically found that if there was any added risk [of shingles] in those groups, it was very minimal, and it was not enough to explain why shingles rates are rising," he says.

Stress is another suspected reason for the spike in shingles cases. "When we have a lot of stress, our immune system gets temporarily diminished," says Jose Montero, MD, a professor of medicine in the Division of Infectious Disease & International Medicine at the University of South Florida Morsani College of Medicine. That temporary weakening might allow the varicella virus to reemerge.

Harpaz has also looked into whether stress is related to the rise in shingles. But he's found no direct evidence that it triggers the illness.

After so much research, are we any closer to knowing what's behind the rise in shingles cases? "In short, no," says Harpaz. "It remains a puzzle."

How to Protect Yourself

Shingles is more than an unsightly rash. After the bumps clear, you can have a long-term, painful complication called postherpetic neuralgia. "This pain can be debilitating in some people," says Montero. "Even a light sensation, like a sheet rubbing against the skin, can cause a lot of pain."

Ochoa's doctor warned her there was a good chance shingles would affect her for the rest of her life. But her rash cleared up within 6 weeks. "Fortunately, I haven't had any side effects," she says.

Crystal Fiereck was also lucky that her shingles pain disappeared with her rash. She was only 12 years old, in sixth grade, when the bumps broke out on her side and back. But her luck changed at age 32, when she got shingles again, this time on the opposite side of her body. "The doctors said it's rare [to get shingles twice], but it can happen," she says. Again the rash faded quickly, but she still has some residual pain from her illness.

Getting vaccinated can dramatically lower your odds of having shingles and its complications. The new vaccine, Shingrix, is more than 90% effective at preventing the disease. It's recommended for people ages 50 and up. You'll need two doses, given 2 to 6 months apart, to be fully protected.

What if you're under 50? You can ask your doctor to give you the vaccine. "The problem is, it's probably not going to be covered by insurance and they will have to pay for it out of pocket," says Harpaz. Most insurance plans will cover the $280 cost for the two-vaccine series, but only if you get Shingrix at the recommended age.

Fiereck asked her doctor about getting vaccinated and was told no. "Insurance wouldn't cover it … and it's an expensive vaccine."

Vaccination may be most important for people whose immune system has been weakened by a disease like cancer or HIV, or by medicines they take. "Those are the patients you really worry about having more serious complications," Montero says. In rare cases, shingles can spread to the brain or spinal cord and cause a stroke or meningitis. Right now, the Shingrix vaccine isn't recommended for people with a weakened immune system, but it is being studied in that group.

Shingrix was introduced only in late 2017, so it's too early to see what impact it's going to have on shingles infection rates. But with the widespread adoption of both the chickenpox vaccine and the new shingles vaccine, the trend should eventually start to reverse, Harpaz says. "Rates of shingles should ultimately decline to low levels."


Show Sources

Annals of Internal Medicine: "Examination of links between herpes zoster incidence and childhood varicella vaccination."

CDC: "Chickenpox VIS," "Frequently Asked Questions About Shingrix," "Shingles (Herpes Zoster): Clinical Overview," "Shingles (Herpes Zoster): Overview," "Shingles Surveillance," "Shingles Vaccination," "What Everyone Should Know About Zostavax."

Clinical Infectious Diseases: "Absence of exposure to varicella does not increase the risk of zoster," "Increasing incidence of herpes zoster over a 60-year period from a population-based study," "Psychological stress as a trigger for herpes zoster: Might the conventional wisdom be wrong?"

Rafael Harpaz, MD, medical epidemiologist, CDC.

JAMA: "Prevalence of immunosuppression among US adults, 2013."

Mayo Clinic Proceedings: "Chronic medical conditions as risk factors for herpes zoster."

Jose Montero, MD, professor of medicine, Division of Infectious Disease & International Medicine, USF Morsani College of Medicine.

Morbidity and Mortality Weekly Report: "Epidemiology of varicella during the 2-dose varicella vaccination program -- United States, 2005-2014."

National Institute of Neurological Disorders and Stroke: "Shingles."

National Institute on Aging: "Shingles."

Postgraduate Medical Journal: "Chickenpox, chickenpox vaccination, and shingles."

© 2018 WebMD, LLC. All rights reserved. View privacy policy and trust info