Talk about shingles and you might think of that quip, "What? Me, worry?" Though it's not an illness on most people's radar, a surprising swath of the American population is vulnerable to shingles, or herpes zoster, an often painful skin rash that can lead to chronic complications. One in three adults can expect to get it in his or her lifetime.
Find out if you might be among the unlucky one million who develop shingles this year.
Have you ever had chicken pox?
Shingles is caused by a reactivation of the same virus that causes chicken pox, varicella zoster. The virus lurks quietly in nerve cells for years, even decades, before suddenly reemerging as a secondary infection of shingles. Roughly one in five people who had chicken pox will later develop shingles.
It's not certain who that 20 percent will be, however. Anyone who's had chicken pox, even a mild case, is vulnerable to shingles -- and that's 99 percent of all American adults over age 40. Those under 40, including children, can also get shingles. The risk of pediatric shingles is especially high in those who had chicken pox before age 1, or if the person's mother had chicken pox in her last month of pregnancy, according to the National Institute of Neurological Disorders and Stroke.
The virus affects the nervous system more deeply with shingles than with chicken pox. This means there's a more concentrated and intense rash, and an increased risk of a lingering pain syndrome called postherpetic neuralgia, or PHN.
Are you under stress?
Stress is one of the more common triggers causing the varicella zoster virus to suddenly flare up again as shingles.
The stress can be sudden in nature, such as a loved one falling into a medical crisis. Or your immunity can be lowered by chronic stress -- excessive work, a bad relationship, the long-term care of someone with Alzheimer's disease, or the extreme fatigue that these situations can cause.
Are you over age 50?
Age is the likeliest risk factor for shingles. Although you can develop shingles at any age after having had chicken pox, the older you get, the more wear and tear your immune system has experienced. And that increases your vulnerability to shingles.
Age 50 seems to be the year when cases begin to rise dramatically. Before age 50, about 2 people in 1,000 get shingles. After age 50, about 6 people in 1,000 get shingles. By age 85, you have a 50 percent chance of getting shingles. More than half of all cases are in people over 60.
Has a close relative had shingles?
A 2008 study at the University of Texas Medical School at Houston found that those with shingles were four times more likely to have had a first-degree relative who'd had shingles in his or her history. The more close relatives you know who had shingles (especially parents or siblings), the higher your risk.
Shingles isn't contagious, however. You can't "catch" it from someone who has it. (Someone who hasn't yet had chicken pox or its vaccination can catch chicken pox from someone with shingles. But you can't get shingles itself.)
Do you have, or have you had, cancer or a serious chronic illness?
Chronic serious diseases known to trigger shingles include diabetes; inflammatory conditions such as lupus, rheumatoid arthritis, and inflammatory bowel disease; emphysema and other forms of chronic obstructive pulmonary disease (COPD); and AIDS.
Add to this list people with chronic kidney disease who are on dialysis. You can't contract shingles from the dialysis process, but kidney illness plus the stress of having dialysis lowers immunity against all kinds of viruses, including herpes zoster, according to the American Association of Kidney Patients.
Cancer -- especially Hodgkin's disease, lymphoma, and leukemia -- can compromise the immune system, either because of the physical stress of the disease itself or the nature of treatments used (such as chemotherapy). Pediatric cancers weaken the immune system from a young age, raising the odds of shingles later in life over those of someone who never had cancer.
Children with asthma also face an increased risk of shingles, according to information from Mayo Clinic researchers in 2012.
Do you take medications that compromise your immunity?
In addition to being more common among those who receive chemotherapy drugs, shingles is more common in people who take immunosuppressive medications, which alter the immune system. These include TNF-alpha blockers such as infliximab (brand name Remicade) and adalimumab (brand name Humira) for rheumatoid arthritis, lupus, and other inflammatory conditions. Medications such as prednisone, for the treatment of these and other autoimmune diseases, such as multiple sclerosis or Crohn's disease and other inflammatory bowel disorders, can likewise be culprits. Protease inhibitors for HIV infection and drugs used in organ transplants also can trigger shingles.
Have you had shingles before?
Most people experience shingles just once. But it's possible to have more than one episode. Doctors aren't sure what causes this to happen, but people who have pain from the initial attack that lasts more than 60 days are more than 5 times as likely to have a recurrence, researchers at Olmsted Medical Center in Rochester, Minnesota, reported in 2009. Among the 1,700 people studied, the time between shingles episodes ranged from 96 days to 10 years. Recurrences were 60 percent more likely in women.