Harvard Health Blog
If you had chickenpox as a kid, there is a good chance you may develop shingles later in life. “In fact, one in three is predicted to get shingles during their lifetime,” says Anne Louise Oaklander, M.D., Ph.D., director of the Nerve Unit at Harvard-affiliated Massachusetts General Hospital.
The same varicella-zoster virus that causes chickenpox also causes shingles. After the telltale spots of chickenpox vanish, the virus lies dormant in your nerve cells near the spinal cord and brain. When your immunity weakens from normal aging or from illnesses or medications, the virus can re-emerge. It then travels along a nerve to trigger a rash in the skin connected to that nerve. The rash often appears on only one side of your body. The most common locations are the chest, back, or stomach, or above one eye.
Most cases of shingles cause severe pain and itching, and can leave scars. Fluid-filled blisters develop, break and crust over during and a few weeks after an outbreak. You also may feel sick or fatigued, with a slight fever or headache. However, it is possible to have rashes that are so mild they’re not even noticed.
Seek treatment right away
Many people have the mistaken impression that, like poison ivy, shingles is a nuisance rash that fades on its own. “But in fact a shingles rash should alert people, especially in middle or old age, to seek immediate medical help,” says Oaklander.
Rapid treatment with one of three antiviral drugs, acyclovir (Zovirax), valacyclovir (Valtrex) or famciclovir (Famvir), can shorten a shingles attack and reduce the risk of serious damage, such as:
Long-term pain. Pain that lingers in the area of a healed shingles rash is called postherpetic neuralgia. This often-disabling pain can last several months to a year.
Prolonged itching. Many people are left with an itchy area from their shingles, which can be as disabling as chronic pain. It is most common on the head or neck.
Damage to vision and hearing. Pain and rash near an eye can cause permanent eye damage and requires an urgent ophthalmological exam. When the nerve to the ear is affected, it can permanently damage hearing or balance.
Strokes and heart attacks. A PLOS Medicine study that tracked about 67,000 people ages 65 and older who were newly diagnosed with shingles found that stroke risk more than doubled in the first week after the shingles diagnosis. The same study reported an increased risk for heart attacks in the three months after shingles, but the additional risk dissipated after six months.
Prevent shingles with vaccination
The Centers for Disease Control and Prevention recommends that almost all people ages 60 and older be vaccinated against shingles, whether or not they had chickenpox in their youth or have had shingles before, says Oaklander.
The vaccination that prevents chickenpox in children was used to develop a similar vaccine (Zostavax) that protects against shingles. “It reduces the risk of getting shingles by about half, and shingles rashes that still develop are slightly less likely to cause postherpetic pain, or other serious complications,” says Oaklander.
People with especially weak immune systems, such as those with cancer or anyone undergoing immunosuppressive treatments, should avoid Zostavax since the vaccine contains a weakened form of the live virus. Because Zostavax has only been available since 2006, it is still not yet clear if a single vaccination offers lifelong protection, but at this time, no booster is recommended.
A new shingles vaccine called HZ/su also may be helpful for older adults. A study published in The New England Journal of Medicine found that the vaccine was 97.2 percent effective among those ages 50 and older, and 97.9 percent effective for those ages 70 and older. And since HZ/su is not made from a live, weakened virus, it is safe to give to people with weak immune systems. This vaccine still needs to undergo further testing before it can be submitted for FDA approval, which may happen as early as this year.
(Matthew Solan is executive editor of Harvard Men’s Health Watch.)