A Patient’s Guide to Shingles

The shingles virus is frighteningly patient. First, the varicella zoster virus causes chickenpox, usually during childhood. Highly contagious, chickenpox can result in a blistering rash that appears across the face, scalp, back and chest. Within a couple weeks, most kids recover, the rash goes away and the memory of chickenpox fades.

Chickenpox can be more serious in some cases, affecting the throat, eyes and other parts of the body, or leading to complications such as dehydration or bacterial infections. Most people develop lifelong immunity and only get chickenpox once.

However, VZV remains in the body, lying dormant around groups of nerve cells. In an unwelcome encore, latent VZV can reactivate many years or even decades later, striking from within as shingles.

Shingles isn't just an adult version of chickenpox. First of all, the appearance is different. It's usually one-sided, with bands of skin rash often confined to either your left or right upper torso. Shingles is painful and the itch is intense and long-lasting.

The impact of shingles can extend beyond skin and scalp rash. If it also affects one side of your face, that can include the eye, posing a threat to your vision. In some cases, you might not even have a rash, as when shingles affects your stomach and gastric system.

In some cases, shingles can leave you with long-lasting effects. Postherpetic neuralgia is a potentially devastating shingles complication. With PHN, your brain and spinal nerves could be damaged. Pain can linger for years. Fortunately, antiviral drugs can treat shingles in its early stages to help avoid complications.

Prevention is possible, as well. Today's shingles vaccine is one of the most effective ever, says Dr. Anne Louise Oaklander, a neurologist and director of the nerve unit at Massachusetts General Hospital, an associate professor of neurology at Harvard Medical School and an international expert on shingles.

Cause

Shingles isn't contagious like chickenpox; you can't directly catch shingles from somebody else who has it. Instead, shingles occurs when VZV in your body "wakes up" and reactivates in nerve cells.

When people recover from chickenpox, the virus is living inside a cluster of neurons called their dorsal root ganglion, Oaklander explains. Peripheral sensory neurons transmit information from the skin, organs, glands and limbs to the brain and spinal cord (central nervous system). These sensory neurons can detect threats and marshal the immune system to protect the body in various ways. Because of their exposed location, peripheral neurons can be affected by viruses in the blood, Oaklander says. VZV is one of those viruses.

Pain and itch are normally protective sensations that tell the body when it's besieged by threats, like touching a hot stove or receiving an insect bite. With shingles, neurons fire off a response without any outside stimulation. "Part of the consequences of damage to these sensory neurons by shingles is the patient begins to feel neuropathic pain, neuropathic itch and other sensations," Oaklander says.

The reason that VZV reactivates in the first place, and why it happens in some people but not others, isn't clear.

Risk Factors

Most adults have latent VZV in their bodies yet the majority do not develop get shingles. However, the virus will reactivate in about 1 in 3 people, according to the National Institute on Aging, part of the National Institutes of Health.

The risk of shingles increases with age, with about half of all cases occurring at 60 or older. Younger people can get shingles, too, although it's rare in people under 40. However, over the past six decades, the incidence of shingles more than quadrupled for people in all age groups, according to a study published in 2016.

If you have a weakened immune system, your risk of shingles is higher because your body has less ability to fight off infections. Factors that can affect your immune system include age, cancer and chemotherapy, HIV infection, overexposure to the sun and transplant drugs used to reduce the chances of organ rejection.

Symptoms

Typically, shingles affect only side of the body in a single area, like the left side of your back. People with shingles have symptoms like these:

Shingles symptoms follow a pattern where rash typically appears after the first skin sensations. Altogether, shingles usually lasts about three to five weeks, with symptoms appearing and resolving in this order:

Shingles resolves completely in most cases, but in other cases, people develop persistent aftereffects.

Eye and Vision

In up to 20% of shingles cases, the patient's eye is affected – referred to as herpes zoster ophthalmicus – if the virus affects the facial area. Cases of herpes zoster ophthalmicus tripled in a 12-year period, according to research from the University of Michigan Kellogg Eye Center in Ann Arbor, presented at a 2019 medical meeting in Vancouver.

Eye or vision involvement in shingles can be quite serious, says study author Dr. Nakul Shekhawat, an ophthalmologist who is now a cornea fellow at the Wilmer Eye Institute at Johns Hopkins Hospital in Baltimore. It can flare up in the eye repeatedly after the first episode, particularly in the cornea, which is extremely sensitive to pain. Moreover, he says, if the condition keeps occurring, it can cause permanent damage and lead to blindness.

Nerve ganglia roots in the head from the fifth cranial nerve, the trigeminal nerve, enables sensation and movement in the face. If VZV reactivates along that nerve, the face can be affected. Typically, only one side of the face, and so only one eye, is involved.

The trigeminal nerve has three branches. The top branch, the ophthalmic nerve, affects the forehead, eyelid, particularly the upper eyelid, and the eyeball. The trigeminal nerve also affects the skin area from the side of the nose up through its tip.

"If you have a rash affecting that skin distribution, you need to get checked by an eye doctor to make sure you don't have any early evidence of eyeball involvement," Shekhawat says.

Sharp, stabbing pain on the surface of the eye is an obvious red flag, but it's not always present. "In some cases, patients can have silent shingles affecting the cornea and other parts of the eye without severe pain," Shekhawat says. "But that can nonetheless lead to visual loss over the long term."

Shingles may also increase pressure within the eye. This can lead to glaucoma, which can affect peripheral vision, and in some cases, cause irreversible vision loss.

Diagnosis

A medical history and physical exam are typically enough for doctors to diagnose shingles. Pain and itch followed by a band of rash on only one side of the body or face are hallmarks of the disease that can help confirm a diagnosis.

A lab test called polymerase chain reaction, or PCR, can identify the viral DNA of shingles. That can be particularly helpful for confirming shingles that occurs without a rash, known as zoster sine herpete.

Some shingles cases may be missed altogether, says Dr. Anne Gershon, a professor of pediatrics and pediatric virologist at Columbia University in New York City. For instance, she's documented a number of extremely mild cases that looked just like insect bites for which most people would never see a doctor.

In some cases, clinicians may culture shingles blisters or take a tissue scraping for testing in the laboratory, to confirm the diagnosis. However, it can be time-consuming to pick up the shingle virus by growing a culture specimen, and it doesn't provide much extra information for patient care, Gershon says.

When shingles is suspected in the gut but no rash is present, saliva testing can identify the VZV affecting the gastrointestinal system, Gershon and colleagues showed in a 2015 study.

Eye Exam

If you have facial shingles, you'll need a comprehensive eye exam from an ophthalmologist to determine if your eye may be affected. Your eye exam will include tests like these:

Getting evaluated for shingles and starting antivirals early can help you avoid potentially sight-affecting complications.

Treatment

If your doctor thinks you have shingles, starting treatment immediately is the priority, rather than waiting for test results to confirm VZV activity.

These prescription oral antiviral drugs are approved to treat shingles in the U.S.

If you even suspect you might have shingles – you don't see the blisters but you have unexplained pain or itch around your body, most often of the trunk or around the eye – you should see your doctor immediately to get started on antivirals, Oaklander says.

When you have an infection in your nervous system, it needs to be treated immediately to spare your nerve, brain and spinal cord cells, Oaklander says: "It's a medical emergency."

Oral antiviral drugs are the mainstay of all shingles treatment, including shingles involving the eye, Shekhawat emphasizes. In addition, some doctors may prescribe topical treatments like eyedrops to treat symptoms involving the cornea.

Once you've started taking antiviral medication, you may also turn to home remedies like applying cool wet compresses to blisters or taking a cool bath to help ease pain and itching.

For severely painful shingles and complications of postherpetic neuralgia, doctors may prescribe treatments including these:

The risk for shingles complications rises with age.

Complications

Postherpetic neuralgia refers to lingering symptoms that follow a case of shingles. Neuropathic itch is one of the major complications of having had shingles, Oaklander says. Burning and stabbing sensations are also common. In addition to its eye and visual effects, shingles can also cause problems with hearing.

Advanced shingles can reach the central nervous system, causing brain and spinal cord damage. Muscular paralysis can occur, compromising limb strength and function. Depending on the nerve damage location, Oaklander says, people can lose the ability to control their bladder or rectum, which can lead to incontinence.

If virus particles enter the cerebrospinal fluid that bathes the brain and spinal cord, you could develop encephalitis or meningitis, Oaklander says: "It can leave you with brain damage, seizures, intellectual impairment or cause death."

Shingles can also infect nerves that go into blood vessels. This can even lead to stroke, which may occur three to four months after shingles appears.

Postherpetic neuralgia must be carefully monitored. Effective medications exist, Oaklander says. She advises seeing a neurologist, internist or pain specialist for treatment. "Particularly if you're in the first few months or (up to) six months afterwards, it may have protective effects and help your neurons to regrow."

Prevention

The good news is that you can take the initiative to stave off shingles. The Centers for Disease Control and Prevention recommends shingles vaccination for healthy adults ages 50 and older.

Two types of shingles vaccines are available for U.S. patients: Shingrix and Zostavax. Of the two, Shingrix is the preferred vaccine, the CDC advises. Here's what you need to know about Shingrix:

Insurance typically covers shingles vaccination for people who meet CDC recommendations. However, many people still don't take advantage of the vaccine, experts say, in part because of practical concerns like the extra step of getting the second dose.

"People don't understand that there's a medical miracle in front of them that could save them from multiple serious neurological illnesses," Oaklander says. "Just go out and get vaccinated. You could protect yourself against stroke, encephalitis, blindness, deafness and against years of pain, itch and anguish."

You can protect your children from developing shingles in later life by making sure they receive routine chickenpox vaccination now. "We don't see chickenpox very much anymore because all the kids are vaccinated – and hopefully will continue to be vaccinated," Gershon says.

Health Care Providers That Treat Shingles

If you have shingles, depending on whether it resolves in a few weeks or leads to postherpetic neuralgia, you could see health care providers including these:

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