More On Shingles

Readers wanting to know more about some topics  pose very good questions. My original magazine column about immunization to prevent shingles (September 2011) generated enough reader mail to warrant another column sharing some of the answers.

Recognizing recurrent shingles episodes:

One reader had suffered through an eruption of ophthalmic shingles, which involves the nerve that carries sensation from the eye, including the cornea, from the skin around the eye, and also from the forehead. The reader wanted to know “What are the signs and symptoms for a re-occurrence of the zoster virus in the eye so I would know what to look for if I am getting an attack?”  As in other areas of the body, symptoms that come before the rash erupts  in the eye and the face are sensory  – tingling, burning, itching and pain. Warning sensations in ophthalmic shingles might also include irritating dryness and a sense something lodged in the eye. Our reader understood that taking an antiviral drug early in the course of an eruption might lessen the likelihood of scarring of the cornea, so paying attention to early symptoms has therapeutic consequences.   If an abnormal sensation persists for several hours without explanation or response to simple measures like rinsing the eye out, then the symptom is worth bringing to the attention of the doctor. That said, the use of antiviral drugs early in the course of a shingles outbreak does not prevent the eruption from progressing, but it may shorten the duration and lessen its intensity.  When the surface of the eye is involved, anything that can be done to prevent corneal scarring is of some value.

Drugs that make the virus awaken

The same reader also wanted to know what drugs might predispose her to another eruption, and how to avoid them. The drugs that put people at most risk for a herpes zoster outbreak are the ones that suppress the function of immune cells in the body. The most common offenders belong to the steroid class on anti-inflammatory drugs, and have names like prednisone, dexamethasone, decadron, and prednisolone.  They are used to treat conditions like multiple sclerosis and lupus and rheumatoid arthritis and when used for periods longer than a week, they begin to impair immune response.  Sometimes they are part of a chemotherapy regimen for cancer. Other chemotherapy drugs and radiation also impair immune cell function, so shingles eruptions are not surprising in patients undergoing cancer treatment.  Paradoxically, steroids are part of the treatment for shingles – but they are used for only a short time, to decrease inflammation.

Vaccine questions

Another reader wrote:” My husband never had Chicken Pox and yet he did have a severe case of shingles and he was in his 40’s when they occurred. At that time we were told the opposite of the article…we were told he got shingles because he had never had Chicken Pox.  This was over 20 years ago so perhaps research has changed that.  Does the fact he had shingles mean he cannot get the vaccine?” There are many people whose childhood chicken pox was so mild that they have no memory of the disease. Blood testing will show whether or not there is any trace of immunity to the virus in people who think they did not have the disease. An adult who contracts chicken pox for the first time has a rash that involves much more of his body than the shingles rash does.  He is also extremely sick, much more so than a child with the disease. So if an adult develops what is a typical shingles rash, it is considered proof that he has had chicken pox in the past.

You probably did have chicken pox

Age 40 is on the young side for shingles, but there are many idiosyncrasies in the immune system, with some people have worse immune “memory” for specific viruses than others do. Having had a shingles eruption does not prevent this reader’s husband from getting the vaccine, and given that it is now over 20 years since the last time the virus stimulated his immune system, immunization might be a very good idea.  Guidelines for vaccine administration also do not exclude people who think they did not have chicken pox as a child, even though, in theory, a vaccine made from a live, weakened virus could cause a full blown case of chicken pox in a chicken pox virgin (more on different vaccine constructions below).  It is estimated that 99% of people in the US have had chickenpox, whether or not they are aware of it.

Being refused the vaccine

Getting an immunization proved difficult for another reader. He went to his county health department seeking a shingles immunization, but he was turned down because he has non-Hodgkin’s lymphoma, a form of lymphatic system cancer. While his disease is in remission and his blood work indicates good immune cell function, there is a theoretical risk that the vaccine, which contains a live, weakened version of the virus, will reactivate the line of white cells that caused his lymphoma. Many people face this type of risk-balancing problem in choosing whether or not to get a vaccine, and each individual case requires weighing risks versus benefits. In some cases, for example someone with AIDS who has good white blood cell tests and is not sick, the patient’s doctor may advise getting the vaccine because the risk of the effect of a shingles outbreak is greater than the risk that the virus in the vaccine will cause trouble. In the case of people with history of cancers that arise directly from immune system cells, however, no one wants to take a chance of triggering cells to become cancerous by the introduction of a live virus in the form of a vaccine.  In addition, no one wants to  introduce an infection that the immune system cannot control.  These problems are the reason that researchers have pushed to develop a new vaccine, just becoming widely available in in 2017-18, which does not contain any live virus.

The old and the new vaccines

Lastly, several readers inquired about the frequency of the zoster vaccination.  Immunizing for shingles is relatively new, and recommendations may change, but right now, Zostavax, the old vaccine, is recommended for all people over age 60,  as a one time shot. Zostavax cuts the rate of shingles by 51% and the development of post-herpetic shingles pain by 65%.  The new vaccine, Shingrix, is recommended beginning at age fifty and in tests improves these prevention rates to 98% and 85% respectively. Shingrix requires two separate doses. The effectiveness of the vaccines does wane over time, and there is more experience with the old one. Currently there are not any guidelines about repeat administration, but there are no contraindications to getting the new vaccine for people who have already had the old one.

Where to get immunized

Immunizations are available at pharmacies, grocery stores, county health offices, and walk in clinics and all of these facilities have guidelines which will exclude some people.  Anyone excluded by general criteria should review the reason with a doctor who cares for the problem that caused the exclusion.

Shingles:Chicken Pox Re-Awakened

Chicken pox is a common and usually mild childhood disease caused by the varicella virus. The  same virus is also the cause of a very painful skin rash known as shingles in adults.  These two very different illnesses demonstrate the two missions of all viruses – to reproduce themselves and to stay alive.   Reproduction keeps the varicella virus spreading from child to child. Hibernation keeps it alive in adults, giving it another chance to reproduce. While chicken pox is usually a mild disease, shingles is painful and at times disabling.

Vaccinations

Since 1995, vaccination against the varicella virus has been very successful in reducing the number of childhood chicken pox cases.  In 2005, a vaccine designed to boost adult immunity cut the number of cases of shingles in adults in half and a vaccine about to be introduced now, in 2017, promises much better protection against shingles for older adults, especially for older adults.  Both chicken pox and shingles vaccines mark significant progress against the varicella virus, which infects 95% of unvaccinated people.

Who gets shingles

Shingles typically afflicts older people or in people with weakened immune systems. In them, the long-sleeping varicella virus has suddenly awakened, erupting in an intensely itchy, blistered rash known confined to one patch of skin, usually on the trunk, but sometimes on the head or extremities. Doctors call shingles herpes zoster, which sometimes causes confusion with the common cold sore, caused by the herpes simplex virus. Both herpes simplex and varicella viruses are members of a larger family of “alphaherpes” viruses, with similar abilities to live in peace inside the body and revive periodically.

Why name it shingles?

Shingles is a more descriptive name than herpes zoster. When fully developed and severe, the shingles rash has a rough, red, pebbled surface formed by multiple blisters packed in tight formation, often rectangular in shape. Like a roof shingle, the patch of virus- laden blisters can look like it has been laid on top of the skin. The distribution of this adult eruption of the varicella virus is very different from the random and widespread distribution of blisters in chicken pox.  The difference between rashes caused by exactly the same virus is a visual lesson in the way the varicella virus infects, reproduces, goes into hiding and reemerges.

The initial infection: chicken pox

The varicella virus enters the body through the nose or mouth. It is picked up by immune cells in the lymphatic fluid and then makes its way through the rest of the body in a trip that takes 7-10 days. Since the immune system doesn’t see the virus as much of a threat, there are often no symptoms of any illness in this period. But once the virus reaches the skin, real battle begins.  Troops of immune cells produce small red dots on the skin, then red bumps and finally blisters which rupture and release new viral particles to the air.  Mission number one, reproduction is accomplished.

The virus goes into hiding

Mission number two, staying alive, is more complicated.  While varicella viruses spread easily from ruptured blisters or via coughing and sneezing, once the viruses dry out, they die.  Dried, crusted rashes are no longer contagious. But underneath the skin, some viruses begin another journey. They travel up long thin nerve fibers that carry sensory information from the skin to the spinal cord. Their first stop is the nerve cell bodies that sit in little clumps of tissue called ganglia, just outside the spinal cord. Here, for reasons that are unknown, the viruses are allowed to integrate their genetic material into the nucleus of the cells, alongside the DNA and RNA responsible for normal protein production.

Re-awakening

For years, varicella viruses demand nothing of their host nerve cells. Then in later life, or sooner in people who have suppressed immune systems from diseases like AIDS  or treatment of diseases like cancer, the varicella virus may suddenly commandeer the protein-making machinery in the  ganglionic nerve cell. It makes multiple copies of itself, sending them back out to the skin along the same nerves by which they entered the ganglia.  The rash that appears affects only the part of the skin innervated by those nerves. The sensory nerves are arranged in “stripes” around the trunk and down the limbs, and the rash looks like a portion of that stripe.

Why the re-awakened virus causes so much pain

Pain is a central feature of shingles because the immune system attacks the virus for a second time. This time, the attack starts in the ganglia where the virus has emerged from hiding. When the immune battle against the virus begins, the nerve cells report the action to the brain, even before a skin rash appears. The unwitting patient begins to feel sharp and shooting pains, as well as numbness, tingling and itching sensations in the skin as long as two or three days before a rash appears. Occasionally fever, headache and back pain appear.  Sometimes pain remains even after the rash resolves, a distressing condition called post-herpetic neuralgia, which is often difficult to manage.

Other complications

Pain is not the only complication of shingles. Permanent damage may result from re-emergence of the virus in a sensory distribution that involves organs other than skin. Rashes that involve the eye can cause scarring the cornea, and those that involve the ear sometimes cause permanent deafness.  Shingles cannot be transmitted, but if someone who has never had chicken pox or been vaccinated against it comes in contact with blister fluid from the shingles rash, they will get chicken pox. Adult chicken pox is a far worse illness than the pediatric version.

Immunity

Immunity to the chicken pox virus diminishes with age, and shingles rarely appears before the late 50s.  About one in every three people who’ve had chicken pox will get shingles;  the risk of a second episode is also about one in three and higher if pain persists more than 30-60 days. Recurrences rarely happen more than twice, indicating that the reawakened virus stimulates renewed immunity.

Avoiding the often disabling pain of an acute shingles episode and diminishing the risk of post-herpetic neuralgia are both good reasons to consider adult immunization against the chicken pox virus. Not only does the adult vaccine cut the risk of getting shingles in half, it makes cases that do occur significantly less severe. The large study that yielded these results also turned up no vaccine safety issues.   When you next think about getting a flu shot, give some consideration to prevention of shingles too.

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